Danny ____________ wears a dress. [ ]
A. usually
B. sometimes
C. never
答案:C
某气体既能用排水法收集,又能用向上排空气法收集,则该气体具有的性质[ ]
A.易溶于水,密度小于空气
B.易溶于水,密度大于空气
C.难溶于水,密度小于空气
D.难溶于水,密度大于空气
引起核黄疸的血清胆红素浓度一般超过()
A.10mg/dl
B.12mg/dl
C.15mg/dl
D.20mg/dl
E.25mg/dl