后边接名词或者形容词，例如：
1.There's only one sure way to do it.做这件事只有一个保险的办法。
2.There were only three of us on the advanced course.只有我们三人学高级课程。
3.Children can be difficult as we know only too well.小孩子往往很难对付，对此我们都非常清楚。
only后面可以接单数,也可以接复数
only one of ...接单数
only a few of 接复数
