_________ is hard is to do well all one’s life and never do anything bad．
A.HeB.ItC.ThatD.What在线课程D
解析：
句首的What is hard是主语从句，注意What is hard后的谓语动词is，假若没有后面的is，则应选B，即说成：It is hard to do well all one’s life and never do anything bad．C项作连接词时在句中没有意义。A项在句中不符的原因是hard不是he本身的特征。