同学你好，该知识点来自沪江网校《新概念英语1、2、3册连读【天猫特惠】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学好：
这部分是讲目的状语的各种表达方式。
1 to catch the train，不定式表示目的。
2 in order to help you，in order to do 表示目的。
3 so as not to disturb him，so as to 表示目的。
【in order to 和so as to 都可以用在句中，二者可替换；但in order to 还可以放在句首，so as to 不可以】
4 in order that he may pass the exams.
5 in order that I might(should) see it.
这两句都是“in order that+从句”表示目的。
6 so that someone would let him out.
这里是“so that+从句”表示目的。
【“in order that +从句”= “so that +从句”，表示“以便...”；in order that 可以在句首，so that 不可以】
7 for someone to let him out. 这是for sb. to do，根据语境，这个整体表示目的。
8 in order that his mother might (should) learn the good news. 同5。
9 for his mother to learn the good news. 同7。

同学给的练习题里，2 和5 填这两个词组都可以，只是答案设定了一个。

祝学习愉快～