要避免液氧泵的汽蚀应注意(),(),(),()等问题。
参考答案:降低泵的安装高度,提高泵的进口压力;加强液氧管路的保冷;空运转的时间不应太长;液氧吸附器预冷要彻底
根据句意,补全单词。
1. The boy wants his father to buy a _____ plane for him as a birthday present.
2. We often play games or go fishing in our _____ time after school.
3. We know Obama is the youngest _____ of the American.
4. Good _____ can help you find good job.
5. There are some _____ in the space such as the earth, the sun and so on.
电源板PWR灯不亮的可能性()。
A.设备电源线未接
B.电源开关未打开
C.空开输入电压异常
D.电源模块故障
E.设备风扇故障