重点讲解：
1. as soon as
一…就…；
eg. As soon as the two chicks hatch, they leave the nest burrow.
两只小鸟一出壳就离开了巢穴。
eg. Let us start as soon as he comes.
等他一来我们就动身。
2. be supposed to
本应该（发生而没有发生）；
eg. They were supposed to be here an hour ago.
他们应该在一小时以前到达这里。
eg. Whoops, you weren't supposed to hear that.
唉，你不该听到这事的。
3. in order to
为了；以便；目的在于；
eg. John and Jack had dropped behind in order to be alone and have a talk.
为了能单独在一起谈谈，约翰和杰克故意走在别人后面。
eg. In order to compass our object we must work hard.
为了达到我们的目标，我们必须努力工作。
