White smoke from a boiler may indicate _______.

White smoke from a boiler may indicate _.A. low fuel oil temperatureB. low fuel

[单选题]White smoke exhausting from an operating diesel engine may indicate （）.A . a cracked linerB . burning lube oilC . an overloaded engineD . insufficient combustion air

[单选题]White smoke __________25～30 meters above the hill as they approached it.A． has been seen riseB． had been seen risingC． was seen riseD． was seen rising

A distorted furnace in a fire-tube auxiliary boiler may be the result of （）A. fi

[单选题]B．lack and white must be ______from each other, must be unable to communicate.A． cut downB． cut outC． cut offD． cut up

[单选题]The author cites the Eskimos not suffering from common colds forever to ind

Nonsmokers often breathe in the smoke from other people’s cigarettes. This is se

[单选题]Mrs. White is different from her friends who were ______.A．easily satisfiedB．not always hopefulC．sure to succeedD．not interested in free food

The next thing he saw was smoke from behind the house．（ ）A. roseB. risingC. to r

[单选题]We may conclude from the text that _____.［A］ human cloning will not succeed unless the technique is more efficient［B］ scientists are optimistic about cloning technique［C］ many people are against the idea of human cloning［D］ cloned animals are more fa