题目

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，从短文后所给各题的四个选项（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。 My father and I were standing at the top of a church tower. He  31  me to this place in a small Italian town not far from our home in Rome. I  32  why he did so. “Look down, Elsa,” Father said to me. I looked down and  33  the square in the centre of the village and I saw many turning streets  34  to the square. “ See, my dear. There is more t地震灾区重建过程中，工人用图示的滑轮组将重400N的建筑材料从地面缓慢提升至l0m高处。已知该工人对绳子的拉力为250N，则此过程人做的总功为_____________J，该滑轮组的效率为__________%。