握手时应该由()先伸手,但在表示欢迎、感谢、祝贺等场合,()也可以先伸手。
参考答案:尊者;卑者
(2012·辽宁高考)This machine is very easy ________. Anybody can learn to use it in a few minutes.
A.operating
B.to be operating
C.operated
D.to operate
胶轮车的摩擦片磨损后,制动器的间隙增大,补偿机构能自动地补偿制动器的间隙。