航空器是指依靠（）的反作用力被支撑在大气中的机器。
A.空气
B.气流
C.风压
D.气压
参考答案：A
—Are you going to the football game this weekend?
—Probably not. The tickets are __________ for me.
A．terrible expensive
B．so much expensive
C．far too expensive
D．highly expensive
