依据《大气污染防治法》，向大气排放粉尘的排污单位，( )采取除尘措施。
A．应当
B．尽量
C．必须
D．可以
参考答案：C
______words and expressions have come into the English language from American English.[ ]
A. A large amount of
B. Masses of
C. A great deal of
D. Many a
凿岩台车的液压油油温应保持在30～70℃范围内，超过( )时，应停止行走。
A．70℃B．65℃C．60℃D．55℃
