— It took me ten years to build up my business, and it almost killed me.

— Well, you know what they say. _____. [ ]

A. There is no smoke without fire

B. Practice makes perfect

C. All roads lead to Rome

D. No pains, no gains

不锈钢管道在油清洗前宜先进行处理的工艺为( )。

A．脱脂
B．酸洗
C．用蒸汽吹净
D．钝化