填空题 1)正常人的眼睛观察25厘米处的物体最清楚.眼睛也不容易感到疲劳.若要使眼睛的像成在距离眼睛25厘米处.眼睛与平面镜的距离应为 . 答 12.5cm 2)如图所示.平面镜M前有一个发光点S.S1是它在镜中所成的像.当平面镜转动一个角度后.像的位置为S2.试作出平面镜的新位置. 3)在“研究平面镜成像的特点 实验中.在桌面竖直立一块 作为平面镜.实验时.要使镜后的物体与镜前相同物体的像完全重合.这是为了 .从而能得到像与物等大.到镜面距离相等的结论. 答:玻璃 比较像与物的大小.和测出像到镜面的距离. 4)池中水的深度是2m.月球到地球的距离为3.8×105km.月球在池中的像到水面的距离是 .水中的月是 像. 答:3.8×105km 虚 5)汽车后视镜是 .而汽车头灯是利用 来反射光的.平面镜可以改变 .如潜水艇上经常用到的 镜.就是这种现象的应用. 答:凸面镜 凹面镜 光路 潜望 6)雄奇险秀的长江三峡景色.自古以来就为文人墨客所称颂.北魏著名地理学家.散文学家郦道元就写下了脍炙人口的名篇.文中写到春冬的美景时.用“素湍绿潭.回清倒影 作了精要的描绘.句中的“倒影 是光的 现象 答:平面镜成像 查看更多

 

题目列表(包括答案和解析)

请先阅读下列短文:
“伽利略”号探测器在木星陨落
“伽利略”号探测器在美国东部时间2003年9月21日纵身跳入木星大气层,以一种近乎自杀的方式使自己焚毁,为长达14年的太空之旅划上了句号.
在地面控制人员的遥控下,2.5吨的探测器逐渐向木星靠近,然后飞人木星黑暗的背面,当天下午4点的时候,它以每秒约48公里的速度坠入木星大气层,按照这一速度,从美国西海岸的洛杉矶到东部的纽约只需82秒.
美国宇航局原打算让“伽利略”号在木星轨道上运行下去,但探测器有关木卫二号“欧罗巴”的表面可能存在海洋的发现使专家们改变了想法,因为“伽利略”号的主要使命不是去外星寻找生命的,所以在设计制造时,探测器并没有经过严格的消毒处理,当它燃料即将用尽时,在木星引力作用下轨道可能发生变化并可能与木卫二号相撞.因此,最终决定在它燃料未完全用尽,还能控制运行轨道之时,让它葬身于木卫二号之外的其它天体上,这个“安葬地”最终定为木星.
请你根据短文完成下列填空题和选择题:
(1)“伽利略”号探测器当初在地球上所受重力为
2.5×104N
2.5×104N
N.(取g=10N/kg)
(2)美国洛杉矶与纽约两地相距约为
3936
3936
km.
(3)“伽利略”号探测器坠入
木星大气层
木星大气层
后,由于高速剧烈
摩擦
摩擦
产生了高温,就将探测器焚毁殆尽,它在自焚过程中将
机械能
机械能
能转化为
能.
(4)美国宇航局改变初衷,决定让探测器自焚的原因可以由以下五句话简单地说明:
①探测器本身没有经过严格的消毒处理
②探测器发现木卫二号的表面可能存在海洋
③木卫二号的海洋中可能有生命存在
④海洋是孕育生命的摇篮
⑤万一与木卫二号相撞,可能导致地球微生物祸害外星生命,上演地球生物入侵宇宙的悲剧
以上五句话的正确排列顺序正确的是(
D
D

A.①②③④⑤;B.②③④⑤①;C.①⑤④③②;D.②④③①⑤

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填空题(本大题有7小题,每空1分,共18分。)
1.我国家庭电路的电压是____V;对人体的安全电压是               V。
2.小聪用伏安法测量电阻R的阻值时,并联在电阻R两端的电压表的示数如图甲所示,与电阻R串联的电流表的示数如图乙所示,则电压表的示数为       V,电流表的示数为       A,电阻R的阻值为         Ω,该导体的两端不加电压时,其电阻值为____Ω。(不计温度对阻值影响)。

3.某物理科技小组设计了汽车有害尾气排放检测电路如甲图所示,R为气敏电阻,其阻值随有害尾气浓度β变化的曲线如图乙所示,R0为定值电阻,电源电压恒定不变。当有害尾气浓度增大时,气敏电阻的阻值将___,电压表的示数将___,电流表的示数将       。(选填“变大”、“变小”或“不变”)

4.如图所示,电源电压保持不变,当开关S闭合后,将滑动变阻器的滑片向右移动时,电压表V的示数将_____,电流表A1的示数将____.电流表A和A1的示数差将_____。(选填“变大”、“不变”或“变小”)

5.在如图电路中,电源电压为6V,R2=4Ω,闭合开关S后,电压表读数为2V,则电流表的示数为___A,电阻R1的阻值为___Ω。

6.电路元件甲和乙中的电流与两端电压的关系如图所示,由图可知,甲的电阻是_____Ω.若将甲、乙并联后接在电压为2V的电源两端,干路中的电流是_______A.

7.在图所示的电路中,电源电压为12V。闭合开关后,滑动变阻器的滑片滑到最左端时,电流表的示数为0.3A;当滑片滑到最右端时电压表的示数为8V,则电阻R1的阻值是__________Ω,变阻器R2的最大阻值是__________Ω.

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阅读下面短文,用括号内所给动词的适当形式填空(必要时可加情态动词或助动词)。
“Everything happens for the best," my grandmother said whenever things weren't going my way. "Don't worry, one day your luck 【小题1】_______(change). "
Grandmother was right, as I discovered after graduating from college. I had decided to be sports announcer (广播员) in a radio station, so I 【小题2】_______ ( go) to Shanghai and knocked on the door of every station. But I got refused every time.
In one station, a kind lady said my problem was short of experience. " Get some work with a small station and 【小题3】_______(work) your way up ," she said.
I couldn't get a job there, either. Then my dad told me a businessman had opened a company and needed someone 【小题4】_______ ( manage) the sports center. But again, I didn't get the job.
I felt really down. "Your luck will change," Granny reminded me. I tried another radio station in Beijing. But the owner, a nice man, told me he already had someone.
As I left his office, I asked, " How can someone be a sports announcer if he 【小题5】_______(not, get) a job in a radio station?"
I 【小题6】_______( wait) for the elevator when I heard the man call, " What was that you said about sports? Do you know anything about football?" I 【小题7】_______(put) in front of a microphone and asked to imagine I was commenting (评论) on a football game. "Now you 【小题8】_______ (watch) the football game between Lu Neng and Shen Hua. . . "
On my way home, Granny's words came back to me, " One day your luck will change, boy. And when it 【小题9】 _______( happen) , it'll feel twice as good because of all the disappointment (失望) you 【小题10】_______ ( have) . " At that moment I knew just what she meant.

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第二节:语法填空(共10小题,每小题1.5分,满分15分)
阅读下面短文,根据上下文在空白处填上适当的词, 或使用括号中的词语的正确形式填空。
We high school students do have some growing pains, but we can get rid of them correctly and wisely.  31           , some of us are upset  32            their body styles and looks. It’s unnecessary and it’s not important at all. We needn’t care about it. It is one’s inner beauty   33           matters. Second, we sometimes seem to be misunderstood     34             our teachers, parents and classmates.    35        (face) with this, we can find a proper time to have a heart-to-heart talk with them, trying to remove the    36                (understand). Some of us have fewer friends. I think being open-minded and friendly will do you good. Third, we may fall behind others,  37           __ makes us stressed. Actually we can encourage    38             to work  39            (efficiency), full of determination. At last, some of us don’t have much pocket money, so they feel unhappy. Isn’t it strange? So long as we have some, that’s enough. And we can learn  40        to spend money.

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第二节:语法填空(共10小题,每小题1.5分,满分15分)
阅读下面短文,根据上下文在空白处填上适当的词, 或使用括号中的词语的正确形式填空。
We high school students do have some growing pains, but we can get rid of them correctly and wisely.  31           , some of us are upset  32            their body styles and looks. It’s unnecessary and it’s not important at all. We needn’t care about it. It is one’s inner beauty   33           matters. Second, we sometimes seem to be misunderstood     34             our teachers, parents and classmates.    35        (face) with this, we can find a proper time to have a heart-to-heart talk with them, trying to remove the    36                (understand). Some of us have fewer friends. I think being open-minded and friendly will do you good. Third, we may fall behind others,  37           __ makes us stressed. Actually we can encourage    38             to work  39            (efficiency), full of determination. At last, some of us don’t have much pocket money, so they feel unhappy. Isn’t it strange? So long as we have some, that’s enough. And we can learn  40        to spend money.

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