“If I ________ taking drugs, I would be a successful businessman now,” said the dying drug addict.

A．didn’t start

B．haven’t started

C．hadn’t started

D．shouldn’t start

牌号27SiMn表示钢中的合金元素Si和Mn的平均含量为：（）。

A.27%

B.小于1.5%

C.大于1.5%

D.等于1.5%