题目

76. Be careful! This kind of disease can be easily ____  _____(传播) everywhere by some animals. 77. After ten            (分钟) rest , they went on working. 78. She lives two floors ___________(在……的上面) me. 79. It took me a long time to choose a present for my son’s _________(20) birthday. 80. How much does the elephant __________(重)? 81. When the traffic light is green ,you can go across the road ____________(安全). 82. My grandfather has a good _________(记忆力). He can remember everything well. 83. I want to go to the supermarket to buy some   �如图所示，是一种开瓶器．使用时将螺旋钻头旋进软木塞，再用双手按压把即可将瓶塞拔出．钻头做得尖细是为了 ．小明将螺旋钻头旋进软木塞后，在6s内将瓶塞拔出，若瓶塞长6cm，瓶塞受到的平均阻力为90N，则小明克服瓶塞阻力做功为 J，其做功的功率为 W．