单项选择题
A.steam engine B.steam turbine C.gas turbine D.diesel engine
The rotating range of the low speed diesel engine is us...
单项选择题The rotating range of the low speed diesel engine is usually lower than （）.
A.100 rpm B.200 rpm C.300 rpm D.500 rpm
Before using or operating any equipment, you should fir...
单项选择题Before using or operating any equipment, you should first （） its manual thoroughly and understand its contents（）.
A.read/sufficient B.consult/sufficiently C.read/sufficiently D.consult/sufficient
When we say that two objects have relative motion, we m...
单项选择题When we say that two objects have relative motion, we mean （）.
A.the distance between them remains the same B.the distance between them is changing C.the position between them is not changing D.their positions to the earth remain the same
