豆腐与珍珠共制的目的是（）

A.降低毒性

B.改变作用部位

C.洁净药物

D.增强疗效

E.缓和药性

— He went to see the man who was in hospital yesterday.    

— _____. [ ]

A. So did we

B. So we did

C. We did so

D. Did so we