你可能感興趣的試題

A tank has been sealed and unventilated for a long period of timeWhich of the following conditions does this indicate?（）

A.The tank is safe to enter
B.The tank is especially dangerous to enter
C.Carbon monoxide is present
D.Water vapor present when the tank was sealed has oxidized

單項選擇題

Fires occurring in combustible metals, such as sodium or magnesium, are classified as a （）.

A.class A
B.class B
C.class C
D.class D