简述链条磨损的原因?
参考答案:
链条过于张紧,两链轮不在同一平面,链条干燥缺油,都会造成链条磨损。
含有优质蛋白质的食物是()
A.馒头
B.豆腐
C.土豆
D.苹果
E.南瓜
The coat was bought two years ago,and I'm afraid it is too small________ me now. [ ]
A. to
B. for
C. about
D. on