怎样判别汽蚀现象？
参考答案：
泵内出现激烈响声；出口压力不稳、严重时打不上量；泵体振动；介质温度升高。
The Chinese Educational Department suggests teachers should receive ________ education to catch up
with the ________ development.[ ]
A．farther；late
B．farther；later
C．further；lately
D．further；latest
It is suggested that a doctor ____immediately.
A．be sent for
B．send for
C．is sent for
D．should send for
