通常情况下,100L空气中氧气占 [ ]
A.21L
B.78L
C.21g
D.21T
答案:A
注射剂灯检的目的是检查
A.微粒异物
B.热原
C.细菌
D.钾离子
E.颜色
The pair of giant pandas called Tuan Tuan and Yuan Yuan _____ the pleasant atmosphere at the Spring Festival Evening Party.[ ]
A. added
B. added to
C. added in
D. added on