亚音速飞行一般指：（）.
A.马赫数低于0.75
B.马赫数0.75到1.2
C.马赫数0.75到1.0
D.马赫数低于1.0
参考答案：A
Yesterday he told me a story ____ in his home town.
A．that had taken place
B．taken place
C．that had happened to
D．happened
They reacted violently _____ the news on yesterday’s newspaper.
A．with
B．against
C．on
D．to
