第16题: [单项选择]A beam of light will not bend round the corners unless ______ to do so with the help of a reflecting device. A. being done B. made C. to be made D. having made 参考答案:B 答案解析:本题为主语承前省略问题。在状语从句中,如果主语的谓语在人称数上和主句一致即可省略。因此,B项实际上相当于it is made,it is被省略。本句大意为:除非装有反射作用的设备,否则一束光不会在角落