4.当must表示“禁止 时.附加问句用must.如: You mustn't do that again, must you? 查看更多

 

题目列表(包括答案和解析)

在物理学中,磁场的强弱用磁感应强度(用字母B表示,国际单位是特斯拉,符号是T)来表示,磁感线越密的地方,磁场越强,磁感应强度B越大.

(1)在图20中,甲为某磁极附近磁感线的方向和分布的示意图,由图可知,该磁极为 ▲ 极,若在l处放置一个小磁针,当小磁针静止时,其指向应是图乙中的  ▲   .
(2)磁敏电阻阻值的大小随磁场的强弱变化而变,图丁是某磁敏电阻R的阻值随磁感应强度B变化的图象,据图线可知,磁敏电阻的阻值随磁感应强度B的增大而▲ .图线没有过坐标原点,说明  ▲  .
(3)王强设计了一个可以测量该磁敏电阻R的电路如图丙所示,(其中磁敏电阻所处的磁场未画出).将该磁敏电阻R放置在磁场中的位置某处,测出电阻后,利用R—B特性曲线可以读出相应的磁感应强度.
①在图甲磁场中1处,测得的数据如图20表中所示,则该磁敏电阻的测量值为 ▲ Ω. 
②根据该磁敏电阻的R-B特性曲线可知,1处的磁感应强度为   ▲    T.
③在实验过程中,仅将磁敏电阻从1处移至2处,其它条件不变,那么电流表的示数
▲   (填“增大”、“减小”或“不变”).
④依据上述方法获得的磁感应强度B的测量值与该点实际值存在不小的误差,为尽可能准确反映空间某点磁场的强弱,你认为在选择磁敏电阻时应注意什么问题?

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如图为人体部分特异性免疫过程的示意图,a、b、c表示细胞。请据图回答下列问题。

(1)该特异性免疫属于       免疫,图中b细胞在人体内可以来自                   细胞。
(2)图中a、b、c、d能够识别抗原的是         。(填字母)
(3)若图中所示的抗原为酿脓链球菌,因其表面的抗原决定簇与人心脏瓣膜上的一种物质的表面结构十分相似,物质d向心脏瓣膜发起进攻,使人患上风湿性心脏病,这属于免疫失调中的             病。
(4)当抗原经过⑤⑥过程时,人体内产生d的主要特点是数量多、速度快,与合成与分泌d有关的细胞器有                      
                      
(5)研究发现,HIV病毒的增殖需要逆转录酶,从遗传物质分析,研究HIV疫苗比较困难的主要原因是                                                          

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阅读短文,翻译画线句子。
     "Be proud of what you do," my father always told me, "whether you are a boss or a cleaner." 1 当我15岁时, I got a summer job in a hospital. I was told that my duties would include sweeping floors, washing dishes and
cleaning toilets. I smiled and remembered dad's words."
     Even though my job was the lowest, 2 It made me feel excited. I regarded it as a challenge 3 因为它是
我的第一份工作.
I learned to be on time and tried to do everything well. In return, I was treated with respect
by doctors, nurses, and patients. Each morning I imagined that the dirty dishes would make patients more sick
if I were not there to wash them clean. After breakfast was done, I started sweeping the floors of all patients'
rooms and cleaning toilets. Though I was tired, I wanted my job to be done well. People would say, 4 "That
young man can always do everything well."

      Working in the hospital taught me that being proud of one's job is very important. I have swept the floors,
and I have been a manager."Be proud of what you do." 5 my father's words have deeply influenced me all my
life
. And I'm sure dad must be proud of me.
1._____________________________________________________________
2._____________________________________________________________
3._____________________________________________________________
4._____________________________________________________________
5._____________________________________________________________

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根据中文意思,完成句子。
1. 我第一次看见小熊猫的时候, 她看起来象一只白色的老鼠.
   When I saw the little giant panda _____________, she _____________ a white mouse.
2. 当你遇到危险时, 一定要让自己镇定.
   When you are ______________, you must tell yourself ______________.
3. 熊喜欢白天四处走动, 很少伤人.
    Bears like ______________ in the daytime and ______________people.
4. 这个地区给野生动物提供食物和居所.是他们的理想家园.
   The area __________ food and shelter __________ wildlife. It's their ___________ home.
5. 观鸟的时候请小声说话并不要随意扔垃圾.
    Please talk ___________ when you watch birds and don't _______________ carelessly.

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附加题:从每小题A、B、C三个选项中,选出能填入空白处的最佳答案。(10分)
小题1:当别人赞扬你时,你应回答      .
A.Thank you.           B.All right.               C.Not at all.
小题2:当你早上遇见老师,可以用“     ”问候.
A.Good morning!        B.Good afternoon!      C.Good evening!
小题3:当你弄坏了别人的玩具,应该说“     ”表示道歉.
A.Thank you            B.How are you?         C.I’m sorry.
小题4:当你向别人介绍李明时,应说“     ”.
A.I’m Li Ming.            B.This is Li Ming.     C.Hello, Li Ming.
小题5:当你向别人告别应说“     ”.
A.Bye-bye!             B.How do you do?       C.Hi!

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