71. I must have this suit _____________.
A.cleared
B.cleaned
C.cleared away
D.cleaned off
答案:B
哪项是沙眼常见合并症()
A.睑球粘连
B.上睑下垂
C.慢性泪囊炎
D.睑内翻及倒睫
E.角膜混浊
目前钻井平台主要采用那种关井方法?有何优点?