重点讲解：
1. decide to do sth. 决定，拿定主意（做）；
Students may decide to seek tutorial guidance.
学生可以决定寻求导师指导jE]uDkFU+Q5vDY_k。
2. be based on 以…为基础；
The treaty was based on a bargain between the French and German governments.
这个条约是以法国和德国政府之间的一个协议为基础的D7FB^YJJImYNLs。
3. back and forth 来回；往返；
I could see the branches of the trees moving back and forth.
我能看到树枝来回摇摆6jgIDWixtn#&2V8Afd=。
4. look for 寻找；
Look for software that's flexible enough for a range of abilities.
寻找功能多、适用性强的软件.TgJhCn^4PS0))StL。