A frontal thunderstorm is caused by ______.A.pronounced local heatingB.wind being pushed up a mountainC.a warm air mass rising over a cold air massD.an increased lapse rate caused by advection of warm surface air

A towing vessel pushing a barge ahead and rigidly connected in a composite unit shall show the lights of ______．

A.A vessel towing by pushing ahead

B.A power-driven vessel，not towing

C.A barge being pushed ahead

D.Either answer A or answer B

Generally, the first action in extinguishing an LFG fire caused by escaping gas is to ______.

A.sweep flames away with water spray

B.shut off the leak

C.use a chemical foam fire extinguisher

D.call the local fire department

A、being unable to finance the cost

B、causing their family a lot of trouble

C、making decisions

D、pain caused by the illness

Advection fog is most commonly caused by ______.

A.air being warmed above the dew point

B.saturation of cold air by rain

C.a rapid cooling of the air near the surface of the Earth at night

D.warm moist air being blown over a colder surface

A、It was we being late.

B、It was our being late.

C、It was we were too late.

D、It was because we were late.