When deeply absorbed in work, _____ he often was, he would forget all about eating or sleeping.

A．that

B．which

C．where

D．when

能凉血化瘀止血，治血热夹瘀的出血证宜首选（）。

A.茜草

B.大蓟

C.蒲黄

D.白及

E.艾叶