某车发动机发出功率为100Kw，传动系损失功率为5Kw，则该车传动系机械效率为（）。
A.95
B.95%
C.5%
D.5
参考答案：B
I want to buy a hat, but there are so many kinds that I can’t decide to take.
A．which
B．when
C．how
D．where
In autumn, the（）fall down from the trees.
A.leaf
B.leafs
C.leaves
