To conserve energy, estate developers are encouraged to build houses that can retain heat in winter.

[问答题]I hope we can have some snow this winter.

[问答题]I hope we can have some snow this winter.

[单选题]Heat energy is a source of power, but （） will cause damage to the engine.A . excessive heatB . insufficient heatC . effective coolingD . high output

[单选题]As a heat engine,（） energy is the source of power by which the diesel engine can be operated.A . electricB . heatC . mechanicalD . exhaust

[单选题]The （） can tell us how much heat we can get from the burning of an oil.A . viscosityB . flash pointC . cetane numberD . calorific value

[单选题]This room ______ cool in summer and warm in winter. It's quite comfortable

[单选题]Sunburn can be just______a heat burn.A.as serveB.severeC.as severe asD.seve

[问答题]Riding bicycles can save energy.

[问答题]Riding bicycles can save energy.

[单选题]I am rather concerned _____her, for I haven't heard from her since last win