3 hour与3hours有什么区别

区别就是两者词性是不一样具体的不同如下

3_hour为形容词性，中文意思是3小时的

Every Saturday, Tani goes to a free 3-hour class to improve his game skills.

3hours为名词，中文意思是3小时Lectures, seminars and tutorials are all one hour in length, whilst laboratory classes usually last either 2 or 3 hours.

区别在于：

第一，3一hour  是个复合形容词，＂三小时的”，在句中作定语。如，

This morning we had a 3一hour meeting.

今日上午我们开了三小时的会议。

I finally got home after a three-hour train ride.

我坐了三小时的火车终于到家了。

It was a three-hour exam.

那是三小时的考试。

第二，3 hours，＂三小时＂，名词复数，句中作宾语。

He has been working for three hours.

他一直工作了三小时。

The flight takes approximately three hours.飞行 时间 大约需要 三 小时。

It rained solidly for three hours.

雨下了整整三个小时。