A320飞机的每个舱门有一个观察窗，在所有发动机关掉和预位系统非预位时客舱压力差在2.5MBAR，则白色指示灯闪烁。
参考答案：错
Nearly half a million people are believed _________ their homes in the past months as a result of the disaster.
A．to leave
B．to have left
C．to be leaving
D．to be left
EI通过键盘命令打开天线命令为（）
