水力清通是利用（）对管道进行冲洗。
A.气流
B.紊流
C.水流
D.对流
参考答案：C
已知∠α与∠β互余，且∠α=35°，则∠β=______°．
There is _____ with your computer. Why not have it _______?[ ]
A. nothing wrong; repaired
B. nothing wrong; repair
C. something wrong; to repair
D. something wrong; repaired
