---Mike’s radio has gone wrong. He will have it ______ tomorrow.

---Why not have Aunt Wang ______ it? Nobody can if she can’t.

A．fix; fixed

B．fix; fix

C．fixed; fixed

D．fixed; fix

摩擦系数小，有较高的精度及寿命的轴承是（）。

A.滑动轴承

B.非金属轴承衬

C.滚动轴承

D.金属轴承衬