教师在给学生们介绍理论，接着举了些具体的例子。我们必须对这里正在讨论的事情保密。写完信后他喝了一杯饮料，然后出去寄信了。谢谢！
參考答案:教师在给学生们介绍理论，接着举了些具体的例子。
The teacher introdced the theory for the students,and then gave some examples.
我们必须对这里正在讨论的事情保密
We have to keep secret for what we are discussing .
写完信后他喝了一杯饮料，然后出去寄信了。
He had a drink after finishing the letter,and then go out to send it.
