The air reservoirs must have _____ fitted to prevent rupture in the event of fire.A.high p

When paralleled, AC generators must have the same _____.

Before liquid can flow into a pump, the air in the suction line must be _____ sufficiently

The soot blowers are operating in the oil fuel boiler the air/fuel ratio must _____ throug

To build the reservoir（水库)， thousands of people have to be_______ .A: relocatedB; repe

John ____ his cap in the air.A、throwB、have thrownC、threwD、throwed

Scientists have concluded that nonsmokers who must______inhale（吸入)the air polluted by to