试题与答案

小李想测量食用油的密度ρ油,他手边的测量工具只有刻度尺。小李利用身边的器材设计出

题型:实验题

题目:

小李想测量食用油的密度ρ,他手边的测量工具只有刻度尺。小李利用身边的器材设计出一个实验方案找来一根均匀轻质直硬棒,用细线系在O点吊起,硬棒在水平位置平衡,将一密度未知的金属块B挂在硬棒左端C处,另外找一个重物A挂在硬棒右端,调节重物A的位置,使硬棒在水平位置平衡, 此时重物挂在硬棒上的位置为D,如图所示,下面是小李测出ρ的部分实验步骤,请你按照小李的实验思路,将实验步骤补充完整。

(1)用刻度尺测出OD的长度l0; 将适量水倒人烧杯(水的密度ρ为已知),金属块B没入水中且不碰烧杯,把重物A从D处移动到E处时(E点未标出),硬棒再次在水平位置平衡,________________,将金属块B取出;

(2)将适量油倒入另一烧杯,金属块B没人油中且不碰烧杯,将重物A从E 处移动到,处时,硬棒再次在水平位置平衡,___________________,将金属块B取出,用抹布擦干;

(3)利用上述测量出的物理量和题中的已知量计算的表达式为:__________。

答案:

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参考答案:A

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题型:阅读理解

阅读理解。

     The day my boyfriend fell to his death,it started to snow,just like any November day,just like the

bottom hadn't fallen out of my world when he freefell off the roof. His body. when I found it,was lightly

covered with snow. It snowed almost every day for the next four months,while I sat on the couch and

watched it pile up. One morning,I shuffled downstairs and was surprised to see a snowplow clearing

my driveway and the bent back of a woman shoveling(铲)my walk. I dropped to my knees,crawled

through the living room. and back upstairs so those good people would not see me. I was embarrassed.

My first thought was, how would I ever repay them? I didn't have the strength to brush my hair let alone

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     Before Jon's death,I took pride in the fact that I rarely asked for help or favors. I defined myself by

my competence and independence. So who was I if I was no longer capable and busy?How could I

respect myself if all I did was sit on the couch every day and watch the snow fall?

     Learning how to receive the love and support that came my way wash't easy. Friends cooked for

me and 1 cried because I eouldn't even help them set the table. "I'm not usually this lazy," I wept. Finally,

my friend Kathy sat down with me and said,"Mary,cooking for you is not a chore. I love you and I want

to do it. It makes me feel good to be able to do something for you. "

     Over and over,I heard similar emotions from the people who supported me during those dark days.

One very wise man told me,"You are not doing nothing. Being fully open to your sorrow may be the

hardest work you will ever do. "

     I am not the person I once wfls,but in many ways I have changed for the better. The fabric of my life

is now woven with gratitude and humility. I have been surprised to. learn that there is incredible freedom

that comes from facing one's worst fear and walking away whole. I believe there is strength in surrender.

1. Which of the following is true according to the passage?

A. The writer's boyfriend died when he fell off the roof he was repairing.

B. The writer had been busy with her life before.

C. The writer recovered from her sorrow quickly with his friend's help.

D. The day her boyfriend died,it was snowing heavily.

2. We can describe the writer before her boyfriend died as the following except      .

A. hard-working      

B. independent      

C. smart        

D. capable

3. The underlined word"shuffled"in Paragraph 1 probably means      .

A. stepped steadily      

B. dragged slowly

C. walked swiftly        

D. slipped sadly

4. We can infer from the passage that      .

A. the writer found her boy friend immediately he fell off the roof

B. the writer became more strong-willed after Jon's death

C. all the people around the writer were friendly and supported her

D. before Jon's death,the writer never asked others for help

5. The writer wrote the passage to      .

A. share her sad story with us

B. express her guilty conscience to the people who helped her

C. show her gratitude to the people who love and support her

D. tell us the changes she has made because of her boyfriend's death

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