重点讲解：
1. back and forth 来回；往返；
例句：I could see the branches of the trees moving back and forth.
我能看到树枝来回摇摆mIgDlpR^Eo!3LtbA7。
2. over and over again 一再；再三；反复；
例句：This is what she has been saying over and over again--I don't know how many times.
这种话，她翻来覆去不知说过多少遍了5ZN7y9M;u(c)Lkr4XP。
3. make sense 可以理解；讲得通；
例句：It all makes sense now.
现在就都讲得通了r;Y6W~T4bd*+VX。
4. one by one 逐个地；依次地；
例句：The students entered the classroom one by one.
学生们一个挨一个地走进教室0Y0]CVYqiNsN!*1Ey7。
5. in other words 换言之；换句话说；也就是说；
例句：In other words, we have to build different corporate cultures and ways of working.
换句话说，我们必须建立不同的企业文化和运作方式-Z2p];+=SEJI|。