A B C D E回答下列問題:(1)實驗中氣體(NO和NO2)發(fā)生裝置應(yīng)選擇 理由是 .(2)要測定m值.需要將C中的溶液進行中和滴定.由于濃硝酸具有強氧化性.能把酸堿指示劑氧化褪色而影響實驗.因此.中和滴定前必須進行的操作是 .(3)裝置的連接順序是(填各裝置接口的編號.連結(jié)膠管及夾持裝置均省略) .(4)連接好裝置.檢查氣密性后.應(yīng)進行兩步必要的操作:第一.打開b.向E裝置右管中加適量水,第二 .(5)實驗前甲.乙兩管液面在同一水平面上.最后讀數(shù)時乙管的液面高于甲管的液面.此時應(yīng)進行的操作是 .(6)實驗后若量氣管中氣體的體積為V(L).C中硝酸的物質(zhì)的量為n.則用含n和V的式子表示m＝ . 【查看更多】

 

題目列表(包括答案和解析)

在某訪談節(jié)目中，五位嘉賓分別回答了來自主持人的五個問題，對少年兒童提出建議。請從下列提問（A, B, C, D, E和F）中選出與嘉賓的回答相匹配的問題。
Questions:

A．Whatwouldyousaytoteenswhoaresufferingfromdepression?B．Doyouhaveanysuggestionsforsomeoneinterestedinyourjob?
C．Doyouhaveanysolutionsforteens’writingdifficulty?
D．What advice can you give a young person on how to be a filmmaker or a writer?
E. Do you have any advice to offer others wishing to become a writer and doctor? 
F. After all these years in the limelight, how do you deal with critics?
1._________________________________________
George Lucas’ answer 
Well, I would say you have to be persistent first of all, because it’s a very hard thing to get into, and it’s very hard to make it because the odds are against you. So you have to really love it; kids who get into it because they think they’re going to make a lot of money or be famous or tell a lot of people what to do all the time will never make it. But if you’re obsessed with film and you love to tell stories and you love writing in that medium, then that will give you the strength to be persistent and make it happen.
2. _________________________________________
Tom Fontana’s answer
I’ve never had writer’s block. I’m trying my luck because I’m hoping never to have it. As far as suggestions, I don’t know. If you write at the same time every day, your brain and your heart will be there, ready to go to work. It’s like how you eat at the same time over the course of the day – you should be available to write at the same time every day. If you have nothing to write, you should still write. Whether you write your name 100 times or describe a banana. If you write for five minutes, and you just get the words down, at least you’re doing something.
3. _________________________________________
Drew Barrymore’s answer
I would just say to persevere and find people who are safe and honest and who will give you tough love and guide you through, because you really can’t do everything on your own. You need love and support around you, and to believe that you will get past these hard times. You will overcome. Things will get better. Life is a series of ups and downs, and the good news is that when you’re in a low, it will always go up again. Life is not a free journey. There are a lot of lessons you have to learn along the way, but just appreciate the gift of it and find people who will be honest with you.
4. _________________________________________
Richard Seltzer’s answer 
Become a doctor first because a writer doesn’t make a living – you have to support yourself and your family. But writing is a very individual thing. It’s like your fingerprint – on one else has exactly your style. A lucky writer will discover his or her style but an unlucky one will always be trying to force himself into an unnatural writing style. It’s uncomfortable, and for them, writing is painful. I’ve never suffered. My life has been a series of small, everyday events. If I feel I have rendered on little bit of life in the most compelling language I can find and am satisfied with it, that is an event I cherish.
5. _________________________________________
Ms. Jamie Hobart’s answer 
It is a long road after medical school and internship but my job is different every day and very interesting. Not everyone can do this job. Autopsies are very different from any other medical job. Here we don't really let anyone under 18 watch or participate in an autopsy. So take a basic anatomy course in college and if you don't mind the cadavers, then you might follow it further. You have to have a very strong stomach and a strong interest in the science. If you decide you really like forensics (the work of scientists who examine evidence in order to help the police solve crimes) but don’t want to do autopsies there are lots of other things in the forensic field like the DNA labor various evidence – related specialties.

查看答案和解析>>

在某訪談節(jié)目中，五位嘉賓分別回答了來自主持人的五個問題，對少年兒童提出建議。請從下列提問（A, B, C, D, E和F）中選出與嘉賓的回答相匹配的問題。

Questions:

A．Whatwouldyousaytoteenswhoaresufferingfromdepression?   B．Doyouhaveanysuggestionsforsomeoneinterestedinyourjob?

C．Doyouhaveanysolutionsforteens’writingdifficulty?

D．What advice can you give a young person on how to be a filmmaker or a writer?   

E. Do you have any advice to offer others wishing to become a writer and doctor? 

F. After all these years in the limelight, how do you deal with critics?

1._________________________________________

George Lucas’ answer 

Well, I would say you have to be persistent first of all, because it’s a very hard thing to get into, and it’s very hard to make it because the odds are against you. So you have to really love it; kids who get into it because they think they’re going to make a lot of money or be famous or tell a lot of people what to do all the time will never make it. But if you’re obsessed with film and you love to tell stories and you love writing in that medium, then that will give you the strength to be persistent and make it happen.

2. _________________________________________

Tom Fontana’s answer

I’ve never had writer’s block. I’m trying my luck because I’m hoping never to have it. As far as suggestions, I don’t know. If you write at the same time every day, your brain and your heart will be there, ready to go to work. It’s like how you eat at the same time over the course of the day – you should be available to write at the same time every day. If you have nothing to write, you should still write. Whether you write your name 100 times or describe a banana. If you write for five minutes, and you just get the words down, at least you’re doing something.

3. _________________________________________

Drew Barrymore’s answer

I would just say to persevere and find people who are safe and honest and who will give you tough love and guide you through, because you really can’t do everything on your own. You need love and support around you, and to believe that you will get past these hard times. You will overcome. Things will get better. Life is a series of ups and downs, and the good news is that when you’re in a low, it will always go up again. Life is not a free journey. There are a lot of lessons you have to learn along the way, but just appreciate the gift of it and find people who will be honest with you.

4. _________________________________________

Richard Seltzer’s answer 

Become a doctor first because a writer doesn’t make a living – you have to support yourself and your family. But writing is a very individual thing. It’s like your fingerprint – on one else has exactly your style. A lucky writer will discover his or her style but an unlucky one will always be trying to force himself into an unnatural writing style. It’s uncomfortable, and for them, writing is painful. I’ve never suffered. My life has been a series of small, everyday events. If I feel I have rendered on little bit of life in the most compelling language I can find and am satisfied with it, that is an event I cherish.

5. _________________________________________

Ms. Jamie Hobart’s answer 

It is a long road after medical school and internship but my job is different every day and very interesting. Not everyone can do this job. Autopsies are very different from any other medical job. Here we don't really let anyone under 18 watch or participate in an autopsy. So take a basic anatomy course in college and if you don't mind the cadavers, then you might follow it further. You have to have a very strong stomach and a strong interest in the science. If you decide you really like forensics (the work of scientists who examine evidence in order to help the police solve crimes) but don’t want to do autopsies there are lots of other things in the forensic field like the DNA labor various evidence – related specialties.

 

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Molly信箱是一個報刊欄目，主持人Molly回答讀者提出的各種問題。第61至65題是五位讀者的來信。請從A、B、C、D、E和F中為每封來信選出最合適的回復(fù)，并在答題紙上將該選項桔號涂黑。選項中一項是多余選項。

Dear Molly,

      I have a problem. My parents are always talking to me about studying. They want me to study harder so I can go to a good school. I know studying is very important, but my parents put too much pressure on me. How can I explain to my parents that I need some free time?

                                                             ------ Overworked

Dear Molly,

       My best friend Tony is a nice young man, but he has a bad habit. He is always late. No matter where he is going to what he is doing, he is never on time. Once he turned up thirty minutes late for a meeting! What can I do to break him of this bad habit?

                                                         ------ Worried

Dear Molly,

       I have a new roommate named Louis. He is a good friend of mine, but he is driving me crazy because he is very untidy. He leaves his dirty clothes everywhere, and he never makes his bed. I am extremely neat. What can I do?

                                                                  ----Unhappy

Dear Molly,

      My cousin plays computer games a lot and he keeps on talking to me about various games. I don’t have any interest at all, but I find it difficult to stop him without hurting his feelings. Would you kindly give me some advice?

                                                                 --- Shy

Dear Molly,

      I’m feeling upset these days because the result of my last English exam was not as good as I had expected. My teacher comforted me, saying “Don’t worry. You can do better next time.” But I’m still feeling bad. I need your help.  

                                                         ----Disappointed

A

B

C

D

E

F

查看答案和解析>>

Molly信箱是一個報刊欄目，主持人Molly回答讀者提出的各種問題。第61至65題是五位讀者的來信。請從A、B、C、D、E和F中為每封來信選出最合適的回復(fù)，并在答題紙上將該選項桔號涂黑。選項中一項是多余選項。

1.Dear Molly,

      I have a problem. My parents are always talking to me about studying. They want me to study harder so I can go to a good school. I know studying is very important, but my parents put too much pressure on me. How can I explain to my parents that I need some free time?

                                                             ------ Overworked

2.Dear Molly,

       My best friend Tony is a nice young man, but he has a bad habit. He is always late. No matter where he is going to what he is doing, he is never on time. Once he turned up thirty minutes late for a meeting! What can I do to break him of this bad habit?

                                                         ------ Worried

3.Dear Molly,

       I have a new roommate named Louis. He is a good friend of mine, but he is driving me crazy because he is very untidy. He leaves his dirty clothes everywhere, and he never makes his bed. I am extremely neat. What can I do?

                                                                  ----Unhappy

4.Dear Molly,

      My cousin plays computer games a lot and he keeps on talking to me about various games. I don’t have any interest at all, but I find it difficult to stop him without hurting his feelings. Would you kindly give me some advice?

                                                                 --- Shy

5.Dear Molly,

      I’m feeling upset these days because the result of my last English exam was not as good as I had expected. My teacher comforted me, saying “Don’t worry. You can do better next time.” But I’m still feeling bad. I need your help.  

                                                         ----Disappointed

 

 

 

 

 

A

B

C

 

 

 

 

 

 

 

D

E

F

 

查看答案和解析>>

任務(wù)型閱讀：Helen 信箱是一個報刊欄目，主持人Helen 回答讀者提出的各種問題。第1至第4題
是4位讀者的來信，請從A. B. C. D. E 中為每封來信選出最合適的回復(fù)，
(     )1. Dear Helen, 
                 I'm a boy in a middle school. My problem is that I want to make friends, but I don't know how.
            My classmates seem to be OK, but I just know I'll do something wrong. Please help me.
                                                                                                                                                  xx
(     )2. Dear Helen,
                 My best friend is a nice young girl, but she has a serious shortcoming. She is always late. When 
            we're planning to do something together, she always keeps me waiting for her. Once she was 30
            minutes late for our meeting. What can I do?
                                                                                                                                                   xx
(     )3. Dear Helen,
                I'm feeling very upset these days because the result of my last English exam was very bad. Even
           though my teacher told me that I could do better the next time, I'm still feeling very bad. I need your
           help. 
                                                                                                                                                   xx
(     )4. Dear Helen, 
                I'm a girl student in a middle school. One day a boy in my class gave me a love letter and he
           wanted me to be his girl friend. I know we are just students and it's not a proper time for me to fall
           in love with somebody. I also do not want to hurt that boy. What can I do?  
                                                                                                                                                    xx
A. Dear xx,
         I understand how you feel about your problem and it's very important for you to find more chances to
     communicate with your classmates. You can ask your classmates about their likes and dislikes. Also, you
     can join them in discussions and show your interest in their ideas. You can change the situation!
                                                                                                                                                  Helen
B. Dear xx,
        You could try talking to her about the importance of being on time, and you can also tell her that you are 
    very unhappy with her about this. If she really cares about your friendship, she will not always keep you 
    waiting for long.
                                                                                                                                                  Helen
C. Dear xx,
         Scores are important for a student, but you don't have to care too much about the result of one test.
     You are learning. Maybe it is more important o find out why you failed to achieve your goal. Try to do
      better next time.
                                                                                                                                                   Helen
D. Dear xx, 
         "Be yourself" is the best solution. If I were you, I'd tell him to leave me alone. At least tell him, "That 
     was hurtful. Please don't say things like that to me. I'm a football fan and like watching football games.
      I can make my own decision."
                                                                                                                                                   Helen
E. Dear xx, 
        You're right. As a student, it's not a proper time for you to fall in love with a boy. If I were you, I would 
     make it clear to the boy that you could not accept his love. If possible, you can tell the boy you two can be
     friends if he can forget it. I hope it can help you. 
                                                                                                                                                   Helen

查看答案和解析>>

1．D【解析】β－珠蛋白DNA探針、RNA聚合酶結(jié)合位點、大腸桿菌質(zhì)粒的化學(xué)本質(zhì)都是DNA；胰島素是蛋白質(zhì)；HIV的遺傳物質(zhì)是RNA；生長素是吲哚乙酸；2，4－D是一種生長素類似物。

2．D【解析】作物“燒心”是由于缺乏如鐵、鈣等在細(xì)胞中以穩(wěn)定化合物形式存在的礦質(zhì)元素，有別于因缺水而造成的“燒苗”。

3．B【解析】疫苗的作用是在機體不患病的情況下發(fā)生免疫反應(yīng)，產(chǎn)生的抗體與抗原結(jié)合，發(fā)揮免疫效應(yīng)；流感病毒的遺傳物質(zhì)是單鏈的RNA，其結(jié)構(gòu)穩(wěn)定性不如天花病毒的雙鏈DNA，容易發(fā)生變異，所以流感疫苗的研究的難度較天花疫苗研究的難度大很多；正是由于流感病毒極易發(fā)生變異，所以某種特定的單克隆抗體不一定對其它的抗原起作用。

4．C【解析】生態(tài)系統(tǒng)的成分除生產(chǎn)者、消費者和分解者外，還包括了非生物的物質(zhì)和能量；生物圈的自給自足表現(xiàn)在物質(zhì)上，能量來源于太陽能；草原上的牛和羊同屬于第二營養(yǎng)級，共獲得生產(chǎn)者固定太陽能的10％～20％。

5．B【解析】考查分泌蛋白的形成和分泌過程這一知識點和圖形分析能力。蛋白質(zhì)分泌以細(xì)胞膜的外排方式實現(xiàn)，所經(jīng)過的膜結(jié)構(gòu)順序為：內(nèi)質(zhì)網(wǎng)→高爾基體→細(xì)胞膜，所以結(jié)果是：內(nèi)質(zhì)網(wǎng)面積減小，高爾基體膜面積不變，細(xì)胞膜面積增加。

6．B　【解析】有機分子的特點一般滿足C四鍵、H一鍵、N三鍵原則，三聚氰胺分子中含有3個－NH2，則其余3個C、3個N形成一個六元環(huán)，故三聚氰胺的結(jié)構(gòu)簡式為。。根據(jù)三聚氰胺的結(jié)構(gòu)簡式，該物質(zhì)不是高聚物，也不是氨基酸，但分子中含有不飽和鍵，在一定條件下能發(fā)生加成反應(yīng)。六元環(huán)不變且除自身外的三聚氰胺的異構(gòu)體有3種。

7．B　  【解析】選項A，Na2O2中含有的陽離子為Na＋，陰離子為O22?,0.1mol  Na218O2中含有的陰陽離子總數(shù)為0.3NA。選項B，C2H4、C3H6的化學(xué)式均為CH2，1.4g二者含有的C原子數(shù)的物質(zhì)的量＝1.4g/14g?mol－1＝0.1mol，即0.1NA。選項C，0.1mol Cl2參與反應(yīng)電子轉(zhuǎn)移0.1mol。選項D，D2O為10電子微粒，18g D2O物質(zhì)的量小于1mol，含有的電子數(shù)也小于NA。

8．A　【解析】選項A，ClO－具有氧化性，SO2具有還原性，SO2被氧化為SO42?，ClO－被還原為Cl?，正確。選項B，加入少許H＋時，CO32?優(yōu)先與H＋結(jié)合生成HCO3?。選項C，離子方程式兩邊電荷不守恒。選項D，Mg2＋能與電解產(chǎn)生的OH?結(jié)合生成難溶性Mg(OH)2沉淀：Mg2＋ + 2Cl? + 2H2O＝Mg(OH)2↓+ H2↑+ Cl2↑。

9. B 【解析】加入稀H2SO4出現(xiàn)白色混濁說明一定存在Ba2＋，因SO32?、CO32?能與Ba2＋結(jié)合生成難溶物BaSO3、BaCO3，所以原溶液中不存在SO32?、CO32?。由于溶液呈電中性，剩下的一種HCO3?，一定存在。無法判斷是否含有K＋，所以原溶液中一定含有Ba2＋、HCO3?，可能含有K＋。溶質(zhì)可能是Ba(HCO3)2或Ba(HCO3)2和KHCO3。

10．D 【解析】根據(jù)題設(shè)條件可推知A為NH4＋，B為OH?，C為NH3，D為H2O。NH3能與H2O反應(yīng)生成NH3?H2O。NH4＋為離子，不是分子，所以NH4＋不是非極性分子。選項D，固態(tài)H2O分子間存在氫鍵，其熔沸點高于固態(tài)H2S，與H－O和H－S鍵強弱無關(guān)。NH4Cl ，NH4＋水解溶液的pH<7。

11．C【解析】分析反應(yīng)①②中各元素的價態(tài)變化可知，反應(yīng)①中，SO2為還原劑，F(xiàn)e3＋為氧化劑，且還原性：SO2>Fe2＋，氧化性：Fe3＋>SO42?。反應(yīng)②中，F(xiàn)e2＋為還原劑，Cr2O72?為氧化劑，且還原性：Fe2＋>Cr3+ ，氧化性：Cr2O72? > Fe3＋。由此可見選項A、B錯誤。選項C，由于Cr2O72?具有氧化性，Na2SO3具有還原性，故Cr2O72? 能將Na2SO3氧化成Na2SO4。選項D，反應(yīng)①中Fe2(SO4)3為氧化劑，反應(yīng)②中Fe2(SO4)3為氧化產(chǎn)物。

12．C【解析】選項A，NaHS、Na2S溶液又因為有HS?、S2?的水解，使其溶液呈堿性，但S2?的水解能力大于HS?，故溶液的pH值：③>②。H2S溶液呈酸性，H2S和NaHS混合液中，由于HS?抑制的H2S的電離，故溶液的pH：④>①，4種溶液pH大小順序為：③>②>④>①。選項B，由于HS?抑制H2S的電離，所以H2S溶液中的c(H2S)小于H2S和Na2S混合液中的c(H2S)。選項C，c(Na＋)＝0.1mol?L-1，根據(jù)物料守恒有：c(H2S) + c(HS?) + c(S2?)＝0.2mol?L-1，故2c(Na＋)＝c(H2S) + c(HS?) + c(S2?)。選項D，根據(jù)電荷守恒有：c(H＋) + c(Na＋)＝c(OH?) + c(HS?) +2 c(S2?)。

13．B　【解析】設(shè)達平衡時生成SO3(g)物質(zhì)的量為2x ，則剩余SO2(g)的物質(zhì)的量為(3－2x)，O2(g)(2－x)，混合氣體總的物質(zhì)的量為（5－x），根據(jù)阿伏伽德羅定律有5/（5－x）＝1/0.9，解得x＝0.5mol，再結(jié)合熱化學(xué)方程式可知，放出的熱量為196.6kJ/2＝98.3kJ。選項B，起始物質(zhì)的量改為 4mol SO2 、 3 mol O2 、2SO3 (g) 相當(dāng)于加入6mol SO2、4mol O2，n(SO2)/n(O2)＝3/2，故與第一次平衡是等效平衡，兩次平衡中SO2的轉(zhuǎn)化率、SO3的體積分?jǐn)?shù)相等，故選項B正確，C錯誤。選項D，題目沒有告訴達平衡時的時間，無法計算反應(yīng)速率。

14．AD【解析】由狀態(tài)方程知溫度升高而壓強增大體積必增大，故狀態(tài)I時氣體的密度比狀態(tài)II時氣體的密度大，A正確，平衡態(tài)II的溫度比狀態(tài)I高，故狀態(tài)I時分子的平均動能比狀態(tài)II時分子的平均動能小，B錯誤，由熱力學(xué)第一定律知從狀態(tài)I到狀態(tài)II過程中溫度升高內(nèi)能變大，體積增大對外界做功，氣體要從外界吸熱，故C錯，D正確，故選AD。

15.答案：BD【解析】：在同一介質(zhì)中紅光傳播速度最大，從AB面射入到BC面射出，紅光用的時間最短，故選項A錯．由于玻璃對紅光折射率最小，對紫光的折射率最大，即紫光的偏折本領(lǐng)最大，所以彩色光帶右邊緣的色光為紅光，左邊緣的色光為紫光，且紫光的頻率比紅光的要高，當(dāng)紅光能讓某金屬板發(fā)生光電效應(yīng)，紫光也一定能夠，故選項B正確．在同樣條件下做雙縫干涉實驗，波長越長，相鄰干涉條紋間距越大，而彩色光帶左邊緣的色光是紫光，其波長最短，故選項C錯．對玻璃而言，在七色光中，紅光的臨界角最大，當(dāng)∠MNB逐漸變小時，射到AC面上的光的入射角變小，且紅光入射角小得更多，故紅光最先從從AC面透出，所以選項D正確．

16、答案 D 【解析】 燒斷細(xì)線后，無論是彈簧將A+B和C彈開過程，還是A和B分離后，系統(tǒng)始終動量守恒、機械能守恒；彈簧將A+B和C彈開過程，A+B和C動量大小相等，動能跟質(zhì)量成反比，因此A+B的總動能是E/3，其中A的動能是E/6；當(dāng)時C的動能是2E/3；前3個選項都錯，可判定D正確。證明：A和B分離時，B+C的總動能是5E/6，B、C共速時彈性勢能最大，當(dāng)時A和B+C動量大小相等，動能跟質(zhì)量成反比，因此B+C的動能是E/12，該過程B+C的動能損失就是此時的彈性勢能，因此Ep=5E/6- E/12=3E/4。

17.答案：ACD【解析】：根據(jù)波的傳播方向，可以判斷b質(zhì)點此時刻振動方向沿y軸負(fù)方向，離開平衡位置，速度正在變小，A對；由圖象可知該波的波長是4m，根據(jù)發(fā)生明顯衍射現(xiàn)象的條件判斷D正確；根據(jù)得，由波干涉條件知C正確；經(jīng)過0.01s即半個周期，任何質(zhì)點通過的路程都是2個振幅，即0.4m，B錯誤.

18．C【解析】從圖(甲)到圖(乙)的過程中，根據(jù)動能定理有：，所以；從拋出后到落地，根據(jù)動能定理得：，代入上式可得：。

19.答案： BC　【解析】此模型為類雙星模型，兩電荷做圓周運動的角速度相等；兩個電荷之間的庫侖力充當(dāng)各自做圓周運動的向心力，所以向心力大小相等，A錯，B對．由知，線速度大小與質(zhì)量成反比，運動半徑與質(zhì)量成反比，C對，D錯．

20.答案：ABD 【解析】天然放射性元素的半衰期與溫度改變無關(guān)。根據(jù)質(zhì)能方程計算可知D答案正確。

21.答案：.D  【解析】地球同步衛(wèi)星是指與地球自轉(zhuǎn)同步的人造衛(wèi)星，它的周期是24小時，它的軌道平面只能在赤道，得軌道也是固定的，但并不是說同一赤道平面內(nèi)的、或是周期與地球自轉(zhuǎn)周期相等的就都是同步衛(wèi)星，故A、C是錯的、D是正確的；同步衛(wèi)星做圓周運動時，內(nèi)部的儀器是處于失重狀態(tài)而不是超重狀態(tài)，B錯

22.答案．（1）(g＋a)× (OM－ON)＝(g－a)× OP    （4分）

【解析】利用紙帶分析得m1帶動m2的加速度為a ,又由牛頓第二定律得a＝解得

⑴3000；（2分）

⑵丙(1分)；乙圖中電流表的示數(shù)太小，誤差太大。丙圖中R的阻值與電壓表阻值接近，誤差小。（3分）。

⑶實物圖連接如右圖所示：(4分)

⑷實驗步驟：

①閉合K1．再閉合K２，讀得電壓表示數(shù)Ｕ１；再斷開K２，讀得電壓表示數(shù)Ｕ２.（2分）�、冢�V＝。（2分）

23.【解析】：（1）負(fù)電……(2分)∵mg =E×……(5分)

∴E=４(r+R)dmg/Rq…………(2分)

（2）mg+q v0B=……………(5分)    ∴v0=mg/qB…………(2分)

24.【解析】：（1）ab通過最大電流時，受力分析如圖甲，此時靜摩擦力最大，，方向沿斜面向下，由平衡條件得：

水平：

（3分）

豎直：（3分）

以上兩式聯(lián)立得出

（3分）

（2）通以最小電流時，ab受力分析如圖乙，此時ab受靜摩擦力，方向沿斜面向上，與（1）類似，由平衡條件得：（3分）

（3）當(dāng)ab中電流最小時，變阻器阻值為：（3分）

當(dāng)ab中電流最強時，變阻器阻值為：，（2分 ）

為保持ab靜止，R的調(diào)節(jié)范圍為0.91~10．（1分）

25.【解析】：（1）設(shè)A物塊碰撞B物塊前后的速度分別為v1和v2，碰撞過程中動量守恒，

  代入數(shù)據(jù)得：        （4分）

（2）設(shè)A、B兩物塊碰撞前后兩物塊組成的系統(tǒng)的機械能分別為E1和E2，機械能的損失為，根據(jù)能的轉(zhuǎn)化和守恒定律：   

     %     （4分）

（3）設(shè)物塊A的初速度為v0，輪胎與冰面的動摩擦因數(shù)為µ，A物塊與B物塊碰撞前，根據(jù)動能定理：                 （3分）

碰后兩物塊共同滑動過程中根據(jù)動能定理：

         （3分）

由、  及（1）、（2）得：    （2分）

設(shè)在冰面上A物塊距離B物塊為L′時，A物塊與B物塊不相撞，

則：                             （4分）

26．（15分）（1）（1）KNO3 （2分）CuSO4（2分）

(2) Na2CO3  （2分）

（3）Al3＋ + 3OH?＝Al(OH)3↓（3分） Al(OH)3 + OH?＝AlO2? + 2H2O （3分）

（4） Al3＋ + 3H2O Al(OH)3（膠體）+ 3H＋ （3分）

【解析】根據(jù)實驗①可知，D中含有Cu2＋；根據(jù)實驗②可知C中含有Al3＋，E可能是KOH或NaOH，再根據(jù)③，只有B、C中含有K＋，故E為NaOH。根據(jù)實驗③A中含有HCO3?，故A為NaHCO3，C、D中含有SO42?，故D為CuSO4，C為KAl(SO4)2。

最后可判定B為KNO3。等物質(zhì)的量的NaHCO3與NaOH反應(yīng)生成Na2CO3和H2O。 NaOH溶液加入到KAl(SO4)2溶液中，首先是Al3＋與OH?反應(yīng)生成Al(OH)3，Al(OH)3沉淀又溶解在過量的NaOH溶液中：Al3＋ + 3OH?＝Al(OH)3↓，Al(OH)3 + OH?＝AlO2? + 2H2O。KAl(SO4)2中的Al3＋水解生成具有吸附作用的Al(OH)3膠體而凈水。

27．（14分）（1）Na2CO3 ＋HCl＝NaHCO3 ＋ NaCl    （3分）

（2）Cl2 + 2OH?＝Cl? + ClO? + H2O （3分）

（3）①Na2O或Na2O2  （4分，每空各2分）②Na或NaOH （4分，每空各2分）

【解析】（1）根據(jù)題設(shè)條件可知，B為鹽酸，C為CO2，D為H2O，E為NaCl。

（2）根據(jù)題設(shè)條件可知B為濃鹽酸，C為Cl2。

（3）若C為O2，D、E的焰色反應(yīng)均為黃色，D、E中含有Na＋，含有Na＋的能產(chǎn)生O2的固體為Na2O2，E能與鹽酸反應(yīng)生成的氣體能使澄清石灰水變混濁，該氣體為CO2，B、E可相互轉(zhuǎn)化，故可推知B溶液為NaHCO3溶液，E為Na2CO3溶液，D為NaOH溶液。Na2O2與NaHCO3溶液反應(yīng)可分解為：2Na2O2 + 2H2O＝4NaOH + O2↑，NaHCO3 + NaOH＝Na2CO3 + H2O。amol NaHCO3→a mol Na2CO3，只要增加a mol Na＋，同時用OH? 將HCO3?轉(zhuǎn)化為CO32? ，所加物質(zhì)所產(chǎn)生的Na＋和OH?的物質(zhì)的量相等，才能不產(chǎn)生雜質(zhì)，故X為Na2O或Na2O2，Y為Na或NaOH。

28．（16分）（1）B（2分）  銅與HNO3反應(yīng)前，應(yīng)排凈裝置內(nèi)的空氣，防止NO與O2發(fā)生反應(yīng) （2分）

（2）將C中的溶液加適量水稀釋（2分）

（3）③④⑤⑨ （3分）

（4）第二，打開a，通足量N2，排凈裝置中的空氣（2分）

（5）向下移動乙管，使甲、乙兩管液面在同一水平面上（2分）
（6）(V－11.2n)/33.6n （3分）

【解析】根據(jù)實驗?zāi)康模蟮胢值，需測定出Cu與HNO3反應(yīng)生成的NO2和NO的物質(zhì)的量，為此需將產(chǎn)生的氣體首先通入裝置C中，H2O吸收NO2生成NO和HNO3，用裝置E測定出NO的體積，如果裝置中有空氣，空氣中的O2會將NO氧化成NO2導(dǎo)致實驗誤差，裝置B通入N2能將裝置中空氣趕走，防止NO被氧化，為此需要的裝置為B、C、E，裝置接口連接順序為③④⑤⑨。由于濃HNO3具有強氧化性，能將指示劑氧化而影響實驗，可加水稀釋降低其氧化性，而溶質(zhì)HNO3的量不變，便于觀察指示劑顏色變化。用裝置E測定NO的體積時，如甲的液面高于乙的液面，測出的NO體積偏小，如甲的液面低于乙的液面，測出的NO體積偏大，故應(yīng)向下移動乙管，使甲、乙兩管液面在同一水平面上，從而減少誤差。根據(jù)反應(yīng)：3NO2 + 2H2O＝2HNO3 + NO，混合氣體中含有NO21.5nmol，NO總的物質(zhì)的量為V/22.4mol，其中屬于Cu與HNO3反應(yīng)生成的NO為（V/22.4－n/2）mol，故M＝（V/22.4－n/2）：1.5n＝(V－11.2n)/33.6n。

29．（15分）（1）取代（或水解）、中和反應(yīng) （2分） （2）HCOOCH3  （2分） HOCH2CHO （2分）

（3）（2分）

  （4）+ 3NaOH+ CH3COONa + 2H2O （3分）

（5） （2分） （2分）

 

【解析】A的分子式為C9H8O4，A能與醇發(fā)生酯化反應(yīng)，說明A中含有－COOH，且A在NaOH溶液中發(fā)生水解生成CH3COONa，說明A中酯的官能團，該官能團與－COOH處于苯環(huán)上的鄰位，再結(jié)合A的分子式推知A的結(jié)構(gòu)簡式為，B為，由于H2CO3的酸性大于酚而小于羧酸，故在溶液中通入CO2時，只有酚的鈉鹽反應(yīng)生成D（）和NaHCO3。CH3COONa與H＋反應(yīng)生成E（CH3COOH）。CH3COOH的同分異構(gòu)體中R中含有－CHO和－OH：HOCH2CHO，Q中含有－CHO而沒有－OH：HCOOCH3。對照和結(jié)構(gòu)可知，首先用與酚羥基反應(yīng)，然后再用酸性KMnO4氧化－CH3為－COOH即可得到A。

30.【解析】（1）新陳代謝是生物最本質(zhì)的特征。（2）人體內(nèi)水的來源包括：飲水、食物中的水、代謝產(chǎn)生的水，人體代謝產(chǎn)生水的途徑有：核糖體上的氨基酸脫水縮合、線粒體中的有氧呼吸等。（3）異化作用類型包括需氧型、厭氧型和兼性厭氧型，根據(jù)材料提供信息，氣性壞疽的異化作用類型為厭氧型。（4）本題考查的是細(xì)胞的選擇透過性，細(xì)胞的功能特性決定于細(xì)胞膜上的載體的種類和數(shù)量

【答案】（12分，每空各2分）（1）新陳代謝現(xiàn)象  （2） 代謝產(chǎn)生水   

氨基酸脫水縮合（或有氧呼吸）      （3）  厭氧型

（4）選擇透過性    載體蛋白 

【解析】由反應(yīng)式：CO2+C5→C3和 2C3學(xué)科網(wǎng)(Zxxk.Com)C5+CH2O可知：一定范圍內(nèi)的CO2增加可以使細(xì)胞中C3增加；一定范圍內(nèi)的光照增強會導(dǎo)致細(xì)胞內(nèi)C5增加。甲圖信息顯示：只考慮光照的影響，光照強度為由n增加到k時，光合速率幾乎不變，而乙圖的變化應(yīng)是光照之外的其他因素引起，比如溫度等

【答案】（10分，每空各2分）（1）低、高、約等于   （2）溫度   

（3）光照強度、CO2濃度、溫度

31．（20分）【解析】：（1）該6個品系玉米的基因型分別為：①：AABBCCDDEE  ②：aaBBCCDDEE  ③：AAbbccDDEE  ④：AABBCCddEE  ⑤：AABBCCDDee  ⑥：aabbccddee

基因分離定律適用于一對等位基因控制的相對性狀的遺傳，基因自由組合定律適用于2對（及以上）的同源染色體上的2對（及以上）等位基因控制的性狀遺傳。具有兩對相對性狀的純合親本雜交，F(xiàn)1自交。若F2中出現(xiàn)性狀分離比為：雙顯∶單顯1∶單顯2∶雙隱＝9∶3∶3∶1，則控制這兩對相對性狀的基因位于2對同源染色體上，反之則位于同一染色體上

讓F1側(cè)交，若F2中出現(xiàn)性狀分離比為：雙顯∶單顯1∶單顯2∶雙隱＝1∶1∶1∶1，則控制這兩對相對性狀的基因位于2對同源染色體上，反之則位于同一染色體上

【答案】（1）②與①（③或、④、⑤） （1分）  不行  （1分）  品系①和⑤只有一對相對性狀   （2分）不行 （1分）  控制花色和種皮顏色的基因位于同一對同源染色體（Ⅰ）上，而控制子葉味道的基因位置未知（2分）

（2）D（1分）

①若綠色非甜子葉∶綠色甜子葉∶黃色非甜子葉∶黃色甜子葉＝9∶3∶3∶1，則控制子葉顏色和味道的基因不是位于同一染色體上。（3分）

②若綠色非甜子葉∶綠色甜子葉∶黃色非甜子葉∶黃色甜子葉≠9∶3∶3∶1（答綠色甜子葉：綠色非甜子葉：黃色非甜子葉＝1：2：1也可），則控制子葉顏色和味道的基因位于同一染色體上。（3分）

（3）

①若綠色非甜子葉∶綠色甜子葉∶黃色非甜子葉∶黃色甜子葉＝1∶1∶1∶1，則控制子葉顏色和味道的基因不是位于同一染色體上。（3分）

②若綠色非甜子葉∶綠色甜子葉∶黃色非甜子葉∶黃色甜子葉≠1∶1∶1∶1（答綠色甜子葉：黃色非甜子葉＝1：1也可），則控制子葉顏色和味道的基因位于同一染色體上。（3分）

 

 

 


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