当冲压空气按钮设置在ON位时，外流活门将：（）.
A.关闭
B.完全都打开
C.当压差小于1PSI时部分打开
D.当压差大于1PSI时打开
参考答案：C
用适当的介词填空。
1. The beautiful dress is _____________ my daughter.
2. They are waiting _____________ the bus.
3. Tom is listening _____________ the radio now.
4. Give the hammer _____________ me, please.
5. He stays _____________ home today
Any one who takes drugs is a danger to the society.
