旅行社终止经营,旅游行政管理部门应退还旅行社质量保证金。 ( )
参考答案:对
— Oh! What's the matter?
— I'm really ______ all the time. I have no energy. [ ]
A. busy
B. happy
C. tired
D. excited
无级调速机车主手柄在前三位时,()触头断开,柴油机转速下降。