生长期儿童锌缺乏的主要表现是A．肠源性肢端皮炎B．克山病C．克汀病D．甲状腺肿E．性成熟延迟

ar intervals, and with the indicator cocks ______, and with the control gear in the ______ position, give the engine at least one complete turn.

A.open / “stop”

B.closed / “stop”

C.open / “start”

D.closed / “start”

A、The start air valve blocked.

B、The turning gear engaged.

C、Start air pressure too low.

D、The governor not connected.

Before starting an engine by air, the engine must .

A.be turned by a turning gear for at least one minute

B.be turned by a turning gear for at least two minutes

C.be turned at least one complete turn

D.be turned at least two complete turns

After the order\

A.the gearbox

B.the steering gear

C.the turning gear

r as a result of turning the wheel ________．

A.Non-follow-up

B.Rudder adjustment

C.Weather adjustment

D.All the above may be activated

action on the liners.

A.the indicators

B.the starting valves

C.the cylinder lubricators

D.the turning gear

Auxiliary machinery covers the steering gear, the turning gear, deck cranes,() and others.

A.main bearings

B.main shafts

C.cargo winches

When turning the engine with turning gear, you should keep the indicator cocks _____.

A.attached to the indicators

B.opened

C.closed

D.broken

A.starting air pressure too high

B.correct timing of starting air valves

C.three of the six starting valves stuck

D.the turning gear disengaged