经寒瘀滞之痛经、经闭当首选（）

A.益母草

B.桂枝

C.赤芍

D.丹参

E.郁金

I was ashamed____ my failing the exam and decided on a measure to make up for it.

A．of; upon

B．for; on

C．at;on

D．about; upon