红外线设备检修完毕后,由()确认后方可正式使用。
A.红外线维修人员
B.红外线调度(值班员)员
C.红外线维修人员和红外线调度(值班员)员
D.红外线调度主任
参考答案:C
No matter how low you consider yourself,there is always someone _______ you wishing they were that high.
A.getting rid of
B.getting along with
C.looking up to
D.looking down upon
只有横波在固体中传播。