英语for和to的用法区别

For years we had little knowledge of what life was like inside China.

以往很多年我们对于中国国内的生活情况所知甚少。

It was a time of peak demand for the product.

那是对该产品需求最旺的时期。

There was much discussion about the reasons for the failure.

就失败的`原因进行了大量的讨论。

The treatment should be repeated every two to three hours.

这种治疗方法应该每隔两到三小时重复一次。

Now she won't have to go out to work any more.

现在她不必再出去工作了。

The need to communicate is a key characteristic of human society.

需要交流是人类社会最重要的一个特征。