to sail have time to do sth.有时间做某事.答案也是这个 那为什么不是 doing sth。呢？为什么一定是有时间做某事？have time to do 是有时间去做，强调的是DO STH，做不定式have time doing sth 是强调所处正在做的某事如果是 have a hard time, time 有形容词hard 修饰的话，后面+doing sth. / with sth .也就是have a hard time doing sth./with sth.记住 have time to do sth.和 have a hard time doing sth./with sth. 这两个搭配就行了哈。