谐波齿轮传动是一种依靠（）运动来实现传动的新型传动。
参考答案：弹性变形
After school we went to the reading-room to do some reading, only to be told that it ____________.
A．was decorated
B．had decorated
C．had been decorating
D．was being decorated
地震灾害的应急处置基本原则包括哪些？
