问题 多选题
如图甲所示,把纸带固定在质量为50g的钩码上,让纸带穿过正确安装的打点计时器,接通电源,然后松开纸带,让钩码自由下落,计时器在纸带上打下一系列的点,得到如图乙所示的纸带.用刻度尺测量起始点O(钩码刚要下落时,打点计时器在纸带上打下的点)到各点的距离,并知道交流电源的频率是50Hz,根据上述数据,在此实验中可以做到(  )

A.测出当地重力加速度的精确值

B.计算出计时器在纸带上打D点时钩码的动能

C.计算出钩码下落过程中受到的合外力大小

D.较准确地验证机械能守恒定律

答案

BCD

完形填空
I was feeling a little blue because my mother had been laid off from her job and she had lots of bills to pay. It left me wondering what was going to happen to us now.
I got off the college shuttle bus and started walking. That’s  36  I heard piano music and singing rising above the noise of the people and the traffic. I walked a little slower so that I could 37   where it was coming from.   38   the crowd I saw a young lady sitting at a piano with a carriage next to her. She was singing songs about love, keeping on trying, and not underestimating (低估) the power within yourself. The way she was singing    39   me a bit. I stood there watching her play for about fifteen minutes, thinking that it must      40   to perform alone in the middle of a crowded place.
She must have felt my   41   because she would  42 look in my direction. Then I walked over and put some  43     in her carriage and she said, “Thank you”. Instead of continuing my way home, I said to her, “I have been  44     a rough time lately, but you’ve made me  45 again.”
“I’m happy that I could help,” she replied. “Why are you so sad?”
“Well, my mum told me she had got    46   from her job, and that made me sad. I’m not so sure what to do …”
“You see, here’s the problem,” she explained. “While you were        47   , your head was down. Don’t look  48 , because  49   comes in different ways and if your head were down, you might lose it.”
She also explained to me that she saw a lot of  50 people in the world and she tried to bring more  51 by sharing motivational (鼓舞人心的) music. She told me that when she wasn’t making music she studied  52  . So, that was how she knew some of the things she was telling me.
I  53     a little wider because I knew that she was doing a good thing. So, after we  54, my heart was  55      and lightened by a musical soul!
小题1:
A.whereB.whyC.whichD.when
小题2:
A.turn outB.take inC.find outD.get in
小题3:
A.AcrossB.ThroughC.BetweenD.Above
小题4:
A.comfortedB.annoyedC.scaredD.reminded
小题5:
A.take timeB.take turnsC.take actionD.take courage
小题6:
A.absenceB.performanceC.presenceD.regret
小题7:
A.angrilyB.occasionallyC.generallyD.faithfully
小题8:
A.cardsB.foodC.booksD.money
小题9:
A.going throughB.getting upC.taking overD.running towards
小题10:
A.curiousB.eagerC.sadD.hopeful
小题11:
A.hiredB.promotedC.paidD.fired
小题12:
A.runningB.drivingC.walkingD.riding
小题13:
A.proudB.defeatedC.absorbedD.puzzled
小题14:
A.opportunityB.troubleC.difficultyD.dream
小题15:
A.positiveB.activeC.energeticD.negative
小题16:
A.recordsB.povertyC.positivityD.indifference
小题17:
A.politicsB.psychologyC.biologyD.art
小题18:
A.smiledB.changedC.influencedD.sighed
小题19:
A.respondedB.partedC.agreedD.understood
小题20:
A.hitB.sunkC.tiedD.touched
问答题