建设单位、施工企业和设计院应组成工程施工安全领导小组，负责工程（）工作的监督、协调。
A.施工质量
B.施工进度
C.施工安全
D.领导责任制
参考答案：C
—Whose pens are there?
—They are ______ They aren't ______. [ ]
A. his; mine
B. mine; him
C. them; theirs
D. her; our
