单项选择题 Some—such as liquid oxygen—are so cold that they embrittle many constructional materials and evaporate continuously if not refrigerated.

单项选择题 Everyone must be responsible for their own behavior, and most of the young people today are interested, as far as I can perceive, in taking their knocks, just as adults must take theirs.

单项选择题 When Joe was left to live with those people, he found that they were so ______ of life that he couldn't stay with them.