樟脑在贮存中容易发生（）
A.变色
B.升华
C.软化融化
D.泛油
E.发霉
参考答案：B
There were so many people on the platform waiting to ____ the train that we gave it up.
A．check
B．carry
C．find
D．board
如果氧气瓶已冻结，严禁用（）来加热解冻。
A、火焰
B、蒸气
C、热水
D、温水
