安全标志是由（）、几何图形和图形符号所构成的，用以表达特定的安全信息。A、安全色B、

A.A

B.B

C.C

D.D

处理上山巷道水灾时，指定专人检测CH₄、CO、H₂S等有毒、有害气体和（）。

One of the best ways for people to keep fit is to _______ healthy eating habits.

A．grow

B．develop

C．increase

D．raise

By the stowage factor, when given a certain volume of space, we know（）.

A.the space of the ship

B.the space of one hold

C.what kind of cargo can be stowed

D.how much cargo can be stowed

有机氮的矿化