排水铸铁管的壁厚为()。
A、4~7mm
B、2~5mm
C、12~18mm
D、7.5~30mm
参考答案:A
--- Have you _____ him to give up the job?
--- Yes, I have. But he doesn’t listen to me.
A.persuaded
B.agreed
C.suggested
D.advised
城市轻轨比公共汽车()等。
A、速度快;
B、效率高;
C、省能源;
D、无空气污染。