入院后第2天，病人突然出现呕血，呕出暗红色血液800ml，此时，对该病人要采取的首要护理措施是()。

A．卧床休息，安慰病人

B．开放静脉通道，补充血容量

C．监测心率、体温、呼吸变化

D．给氧

E．血红蛋白测定

— Why does she look so tired?

— She ____homework all the morning and she still hasn't finished it. [ ]

A. is doing

B. has done

C. has been doing

D. was doing