I regret            you that Tom failed the exams. He regretted            your advice. [ ]

A. to tell; not to follow

B. telling; not following

C. to tell; not following

D. telling; not to follow

以下哪个不是AxiosX荧光光谱仪外循环水系统的作用。（）

A、冷却内循环水

B、使机箱恒温

C、冷却X光管阴极灯丝

D、冷却X光管阳极靶