收缩时使声带松弛，同时兼有声带内收、关闭声门功能的是：（）
A．环杓后肌
B．环杓侧肌和杓肌
C．环甲肌
D．甲杓肌
E．杓会厌肌
参考答案：D
The boss said we had only three days to finish the work.
Don’t worry. We have already ____? two thirds of it.
A．got down
B．got through
C．given in
D．given away
AG—Ⅲ检波器属于（）式地震检波器。
A、电动
B、涡流
C、压电
D、激光
