To launch a liferaft by hand you should（）.

A.cut the casing bands，throw the liferaft over the side，and it will then inflate

B.detach the operating cord，throw the raft over the side，and it will then inflate

C.cut the casing bands，throw the raft over the side，and pull the operating cord

D.throw the liferaft over the side and pull the operating cord

在砂浆使用过程中，最高气温超过30摄氏度时，应在（）小时内使用完毕。

A、1.5

B、1

C、2

D、3