can not:
不能；不可以
Some food can not be stored.
有些食物不能贮存。
unable:
adj. 不会的，不能的；[劳经] 无能力的；不能胜任的
She is unable to conceive.
她不能怀孕。
The system is unable to log you on.
这个系统无法让你登录。
She was unable to keep back her tears.
她无法忍住泪水。
I was unable to shake off my self-pity.
我无法从自怜中摆脱出来。
