喷射混凝土施工时,所用的速凝剂、其初凝时间不应超过()
A.10min
B.15min
C.5min
D.3min
参考答案:C
对阴阳偏衰采用的治疗原则是()。
A.损其有余
B.补其不足
C.寒者热之
D.热者寒之
E.实则泻之
John waited at the bus-stop for nearly half an hour _____ the bus finally arrived .
A.when
B.as
C.before
D.while