一个10W的功率信号，经过一个衰减器（其损耗为6dB）之后，功率为（）。
A、10W
B、1W
C、5W
D、2.5W
参考答案：D
____， he never seems able to do the work beautifully.
A．Try as he does
B．As he tries
C．Try as does he
D．As try he does
如果卖方在进口国没有分支机构及特别的合作伙伴，则不宜选用的贸易术语是( )。
A．CIP B．EXW C．FOB D．DOP
