六年级英语句式变换

题目

六年级英语句式变换
People can only live for a few days if there is no warter.= people can only live for a few days without water.
中for可以换为in吗,为什么?

答案

不可以.for表示一段时间.
He will come in a few days.他几天后来.
He will stay for a few days.他会待几天.