重点单词用法
1. differ vi. 不同于，不一样，有区别；有异议，（意见）有分歧
1) The two systems differ in many respects. 这两种系统在许多方面不同。
2) People differ from one another in their ability to handle stress.在应对压力方面人们的能力各不相同。
3) Human facial expressions differ from those of animals in the degree to which they can be controlled on
purpose.
