I was giving a talk to a large group of people, the same talk I  _____ half a dozen other groups before.[ ]

A. was giving

B. had given

C. am giving

D. have given

对慢性肾小球肾炎患者病情观察应注意（）

A.有无尿毒症早期征象，如头痛、嗜睡等

B.准确记录尿量

C.注意观察血压的变化

D.注意有无电解质紊乱和发生高、低血钾等

E.补充大量蛋白质，供给足够热量