In the USA, he made a lot of friends ______ English well to make himself ______.

A．learn; understand 　

B．to learn; understood

C．learning; understand

D．learned; understood

审核范围和准则应由（）根据审核方案程序确定。

A.审核组长

B.审核委托方

C.审核组

D.受审核方