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科目: 来源: 题型:

(10分)某同学在探究“物体的质量跟体积的关系” 的实验中,

(1)他将托盘天平放在水平桌面上,把游码移到标尺左端
的“0”刻度线处,观察指针的指示情况如图(甲)所示,此时应进行的操作是                  。天平横梁调平衡后,在称物体的质量时,他在天平右盘中加、减砝码后,指针的
指示情况如图(乙)所示(1)这时他应进行的
操作是                          
(2)右表是这位同学记录的实验内容和实验数据,请你根据表格中记录的内容和数据,进行分析比较:
①铁和铝两种不同物质的相同点是:
                                              
不同点是:                              
②铁的密度为                Kg/m3
③根据这个实验的结果,请你分析并回答,为什么说密度是物质的特性?
                                                                                             
                                                                            
④做这个实验时要选取多种物质,且对每种物质都要收集多组数据。为什么?
                                                                            
                                         
 
 
物理

物体
质量
/g
体积/cm3
质量跟体
积的比值/
g/cm3
铁块1
79
10
7.9
铁块2
158
20
7.9
铁块3
237
30
7.9
铝块1
54
20
2.7
铝块2
108
40
2.7
铝块3
162
60
2.7
 

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下列说法中正确的是(     )
A.一桶水的比热容比一杯水的比热容大
B.水壶里的水烧开时,水蒸气把壶盖顶起,机械能转化为内能
C.用锯条锯木板时,锯条发热,锯条的内能没有增加
D.糖放入水中,过一段时间后整杯水都变甜了,表明分子在不停地做无规则运动

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蹦床运动是运动员从蹦床弹向空中表演技巧动作的一项体育活动。当运动员离开蹦床弹向空中的过程中,运动员具有的(   )
A.动能增加,势能减少B.动能增加,势能增加
C.动能减少,势能减少D.动能减少,势能增加

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某汽油机飞轮的转速为2400R/min,该汽油机每秒钟对外做功(   )
A.1200次B.40次
C.20次D.10次

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如图所示,闭合开关S时,小电灯L1、L2都不亮。用一段导线的两端接触a、b两点时,两灯都不亮;接触b、c两点时,两灯也不亮;接触a、d两点时,两灯都亮。对此,下列判断中正确的是(    )
A.灯L1 断路B.灯L2断路C.开关S断路D.灯L2短路

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科目: 来源: 题型:阅读理解

People say teenagers are no good. They make too much noise in shopping malls; they drive recklessly(不顾一切地) up and down America’s main streets; they carry chips on their shoulders as big as the Sears Tower. And at least some of the time those things are true. But we shouldn’t forget that there are hard moments in the life of a teenager too.
I watched such a moment not long ago at a woman’s funeral. I didn’t expect the event to affect me. Through much of the ceremony, in fact, I remained unmoved.
The teenage grandson stepped forward. With his very first deep breath, every heart in that church was achingly reminded of something we had all forgotten. Softly he began: “I want to share a few values that Nana taught me. She never failed to see light in any situation. When our family dog would truely attract her, what would Nana say? ‘oh, what beautiful barking that dog has!’ That was Nana. ”
“She was a strong woman who often lived in the shadow of my grandpa, who was a successful businessman in this city. But she was the one behind the scenes who provided the strength and support for my grandpa’s career,” he said, with a voice now trembling, “That was Nana’s way.”
Through a low sob, he continued, “Whenever she did anything worth recognition, you’d have to hear about it from a different source, because she was never one to show off.”
Finally, in a voice breaking free of sorrow, he looked up and said, “Nana taught me courage. She put up an incredible fight to the end, when she died peacefully, which is how she lived her life. That was Nana’s way, and I hope I can carry on in the same manner.”
There are no hearts as sensitive as those of teenagers, because everything is happening to them for the first time. The trouble with teenagers is that they haven’t learned to be controlled.
When that boy rose to speak about the woman who surely had been his truest and dearest friend, his honest voice dragged each of us out into the open where we could no longer hide in the calm ceremony . He exposed us to the truth about this very real woman who believed in a boy who probably tried the patience of many adults. He reminded us that his grandmother was more than another dot on the chart of life and death.
All over again we felt those powerful losses crossing our own hearts, and we knew that when you say good-bye to something happy, something young in yourself. And that something never really returns, and the pain never really goes away.
【小题1】In the first paragraph, the writer gave some examples to_____.
A.support his idea that young people are no good.
B.introduce his point of view about young people.
C.tell people every coin has its two sides.
D.young people often make mistakes.
【小题2】 From the boy’s speech, we know _____.
A.his grandmother had great influence on him.
B.they had a dog which often attacked people
C.people had forgotten her until the boy appeared..
D.his grandmother was so weak that she is always living in the shadow of his grandpa
【小题3】 Which of the following statements is true?
A.The boy ‘s speech moved no one present at the funeral except the writer.
B.The boy’s being good at expressing himself enabled him to draw everyone’s attention.
C.The boy was too grievedto accept the fact that his grandmother had passed away.
D.The writer didn’t expect the event would affect him.
【小题4】What words can best describe grandmother’s quality?
A. weak, mild and modest.
B.. easygoing, cautious and considerate
C. sensitive and hard on others.
D, patient, optimistic, strong and helpful.
【小题5】The passage tells the readers____.
A.facing certain bitter facts help young people to grow.
B.young people have to control themselves
C.the adults should learn from the young.
D.the adults should teach the young how to be brave

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关于公式R=U/I,以下说法中正确的是(   )
A.导体的电阻与电压成正比,与电流成反比
B.加在导体两端的电压越大,则电阻越大
C.当导体两端的电压为零时,导体的电阻也为零
D.导体的电阻在数值上等于电压与电流的比值,电阻是导体本身的性质

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两定值电阻甲、乙的电流与电压关系图像如图所示,现在将甲和乙并联后接在电压为3V的电源两端.下列分析正确的是(    )
A.甲的电阻是乙的电阻的两倍B.甲的电压是乙的电压的两倍
C.流过甲的电流是流过乙的两倍D.流过乙的电流是流过甲的两倍

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如图所示,电源电压保持不变,当变阻器滑片P滑到A端时,闭合开关S1和S2,灯泡L恰好正常发光,以下说法正确的是(  )
A.滑片P仍在A端,开关S1断开,S2闭合,灯泡L仍正常发光
B.滑片P仍在A端,开关S1闭合,S2断开,灯泡L仍正常发光
C.滑片P滑到B端,同时闭合开关S1和S2,灯泡L仍正常发光
D.滑片P滑到B端,开关S1闭合,S2断开,灯泡L仍正常发光

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清华大学的虞昊教授致力于第三代照明技术——LED灯的普及工作。LED灯的能耗小,造价低廉,使用寿命长。虞昊自制的LED台灯,用电压为6伏的电源供电,正常工作电流为300毫安。那么,此LED台灯正常工作时的功率为(    )
A.1.8瓦B.18瓦C.180 瓦D.1800

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