卷扬机卷筒的中心至最近一个滑车的距离应大于卷筒长度的（）倍。
A.10；
B.12；
C.15；
D.20
参考答案：D
驾驶时，应多用传动比（）的档以便于改善燃油经济性。
91.You will find as you read fiats book that you just can’t keep some of these stones to ______. You will want to share them with a friend.
A．itself
B．yourself
C．himself
D．themselves
