题目

 Easter Island, which was almost uninhabited when it was discovered on Easter Day in 1722 by a Dutch captain, is covered with hundreds of giant statues, each _______ several tons.   A. weighing           B. weighs          C. weighed          D. to weigh 答案：A5、如图所示，1、2为物镜长度，3、4为目镜长度；5、6为观察时物镜与切片的距离。欲获得最大放大倍数的观察效果，其正确组合是（　） A．1、3、5       B．2、4、6       C．2、3、5       D．2、4、5