个人认为4个
1。为了travel
2.international student 可以回家服兵役
3.学了12年之后休息一下
4.花在他们感兴趣的事情上
答:four
1 Have a chance to travel
2 Give students a chance to explore their interests
3 Have a chance to recover after twelve years of required deucation
4 Have a chance to explore interests
Four reaseans were mentioned in the article as follow,
1. To have a chance to travel
2. For international student, to meet requirements at home for military duty
3. To have a chance to recover after twelve years of required education.
4. To have a chance to explore interests.