题目

在“探究加速度与质量和力关系”实验中，实验装置如图甲所示若实验中采用电火花打点计时器，则所用的电源是______A.直流电源 交流电源 直流电源 交流电源实验中平衡小车所受阻力的做法是：在不挂细绳和钩码的情况下，改变板的倾斜程度，使小车能拖动纸带沿木板做______运动；如图乙是实验中打出的一条纸带，在纸带上每5个点取1个计数点，得到O、A、B、C、D几个计数，用刻度尺量得、、、。由此可知，纸带做______运动选填“匀加速”或“匀减速 第二节  完形填空（共20小题；每小题1.5分，满分30分） 阅读下面短文，从短文后各题所给的四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。    When I was a teenager, I volunteered to work at the water station for 10km race. My job was to pass out water to the   36  . I saw all kinds of people passing by and thought maybe I can do it too! So the next year I   37   up for the race. I didn’t do much to   38   except jog around my neighborhood and I had no specialized training, no game plan, nothing. My only goal was to   39   the race.    On the day of the race, it was extremely hot. I remember   40   at the 7th kilometer, thinking, “I must be   41  ; why do I do this? I will never do this again!” That first 10km race was quite a(n)  42  . I jogged and I walked．At times, I didn’t know if I could finish.    At one point near the end, an old man ran past me, and I felt   43   that I, a 20-year-old, couldn’t even keep up with a 70-year-old．But then I   44   something. He was running his race and I was running mine. He had different abilities, experience, training and   45   for himself. I had mine. My goal was merely to finish.    How   46   in life do we compare ourselves with others and feel disappointed in ourselves when we really shouldn’t?    After a minute, it   47   to me that this was a lesson I could draw from. I turned my embarrassment into inspiration. I decided that I would not   48   running races. In fact, I would run even more races and I would learn how to make full preparations   49   and one day I would be one of those old but energetic runners.   50   I crossed the finish line, I was   51   of my achievement. In life we all have those moments when we   52   ourselves with others. It’s only natural. But don’t   53   them to weaken you. Turn them into   54   and let them lift you up. Use them to show you what is   55  . Live with your dreams and you are a winner! 36．A．runners            B．volunteers        C. joggers                  D．trainers 37．A．followed          B．attempted         C. took                  D．signed 38．A．prepare            B．plan                C. practice             D．help 39．A．win              B．finish                  C. participate         D．inspect 40．A．wandering           B．resting             C. struggling          D．hesitating 41．A．tired             B．crazy            C. ridiculous          D．teased 42．A．mistake           B．amusement   C. decision              D．experience 43．A．discouraged     B．confused          C. annoyed            D．embarrassed 44．A．sensed             B．realized           C. recognized      D．acquired 45．A．goal             B．age                  C. income              D．thought 46．A．much                  B．long                C. often              D．soon 47．A．occurred        B．appealed          C. reminded           D．appeared 48．A．give out           B．give up            C. give in                  D．give off 49．A．timely             B．delightedly       C. properly            D．personally 50．A．Unless             B．When                  C. Since          D．Until 51．A．proud              B．ashamed       C. doubtful            D．sure 52．A．cooperate       B．compare          C. combine            D．communicate 53．A．allow                  B．expect          C. discourage         D．forbid 54．A．information     B．imagination      C. qualification      D．inspiration 55．A．unbelievable    B．reliable            C. valuable            D．possible