欲进行肺癌危险因素的病例对照研究,下列不能作为对照的是()
A.支气管炎病人
B.胃病病人
C.意外损伤病人
D.肠道传染病人
E.眼病病人
参考答案:A
有清热燥湿,泻火解毒,退虚热功效的中药是()
A.黄芩
B.黄连
C.黄柏
D.龙胆草
E.苦参
---So you are back; are all the students present at the meeting?
---Not really, nobody but Lucy and John ___________ in the meeting room.
A.are
B.were
C.was
D.is