It's very hot today. You can _____ your coat, Jack. [ ]
A. put on
B. take off
C. wear
答案:B
下面表达系统为原核表达系统的是()。
A.E.coli
B.毕赤酵母
C.昆虫细胞
D.动物细胞
泪道冲洗时,水由下泪小点进入,自下泪小点流出,未见脓性分泌物,其诊断为()
A.泪小管阻塞
B.泪小点闭塞
C.泪小管炎
D.慢性泪囊炎
E.鼻泪道阻塞