—Where is your pencil?
—______ is in my bag. [ ]
A. Its
B. It's
C. It
答案:C
支气管异物的间接X线征象中不包括下列哪项()
A.肺不张
B.肺部感染
C.纵隔摆动
D.横"S"征
E.阻塞性肺气肿
压力容器按安全监察方面分类,可分为一类容器、二类容器和三类容器。