A.2s,24hB.2s,12hC.3s,24hD.3s,12h
A.IxB.W/m2C.WD.A
A.3倍,6點(diǎn)B.3倍,5點(diǎn)C.2倍,6點(diǎn)D.2倍,5點(diǎn)