题目

如果让你为下次 “天宫课堂 ” 设计物理实验和活动，能够完成的是（ ） A．用天平测冰墩墩的质量 B．验证牛顿第一定律 C．托里拆利测大气压实验 D．验证阿基米德原理 答案：B【解析】 【详解】 A．天平是利用杠杆平衡条件的原理，太空中为失重环境，可认为物体不受重力作用，对天平没有压力，用天平测量冰墩墩的质量不能完成，故 A 不符合题意； B．物体在不受力时总是保持静止或匀速直线运动状态，太空中为失重环境，可认为物体不受重力作用，可以用来验证牛顿完形填空（共20小题；每小题1.5分，满分30分） One morning I wasted nearly an hour watching a tiny ant carry a huge feather. Several times, it   36  several obstacles in its path. And after a brief pause it would make the necessary detour (绕道).   37  one point, the ant had to cross a crack(裂缝) about 10mm wide. After some   38   thoughts, the ant laid the feather over the crack, walked   39  it and picked the feather up on the other side, then continued on its way. I was   40  by the cleverness of this ant. It was only a small insect, lacking in   41  yet equipped with a brain to reason, explore, discover and overcome.   42   this ant, like the other two-legged creatures   43  on the earth, also shares human failings. After some time the ant   44  reached its destination — a flower bed and a small hole that was the entrance to its   45  home. It was there that the ant met its   46   . How could that large feather possibly   47  such a small hole? Of course, it couldn’t. So the ant, after all this   48  and using great brightness, overcoming problems a1l along the way, just gave up the   49  and went home. The ant had not thought the problem through   50  it began its journey and in the end the feather was   51  more than a burden. Isn’t our   52  like that? We worry about our families; we worry about the   53  of money; and we worry about all kinds of things. These are all burdens — the things we pick up along life’s path, and drag them around the obstacles and over the cracks that life will bring, only to   54  that at the destination they are   55  and we can’t take them with us. 1.                A．came across     B．came about      C．got over D．took over 2.                A．For            B．At             C．To   D．With 3.                A．brave          B．tiring           C．short     D．magic 4.                A．through        B．across          C．beside    D．behind 5.                A．satisfied        B．frightened       C．annoyed D．attracted 6.                A．height          B．size            C．depth    D．width 7.                A．Therefore       B．Otherwise       C．But D．Moreover 8.                A．living           B．working         C．sleeping D．walking 9.                A．finally          B．probably        C．suddenly  D．easily 10.               A．lonely          B．comfortable     C．underground   D．big 11.               A．partner        B．parent         C．match D．friend 12.               A．fix            B．fit             C．fill   D．feel 13.               A．trouble         B．pleasure        C．decision   D．matter 14.               A．insect          B．problem        C．feather    D．hole 15.               A．before         B．after           C．until  D．once 16.               A．everything      B．anything        C．something D．nothing 17.               A．study          B．aim            C．dream D．1ife 18.               A．waste          B．lack            C．worth     D．danger 19.               A．think          B．wonder        C．warn D．find 20.               A．bad           B．useless         C．meaningful D．practical