采煤工作面所有安全出口与巷道连接处()米范围内必须加强支护。
A、15
B、30
C、20
参考答案:C
常用于创面溃疡的膏药有()。
A.太乙膏
B.万应膏
C.万灵膏
D.损伤风湿膏
E.陀僧膏
— I'm leaving now.
— ______ you turn off the lights. [ ]
A. To make sure
B. Make sure
C. Made sure
D. Making sure