英文原文
Not Necessary To Answer

Teacher：“I have two questions，it isn't necessary to answer the second question if you know the result of the first question．How much hair do you have？”

Student ：“A hundred and twenty millions．”

Teacher：“How do you know it？”

Student：“It is not necessary to answer the second question．”

参考翻译
无需回答

老师：“我有两个题目，你若能答出第一题就不需答第二题。你有多少根头发？”

学生：“１．２亿根。”

老师：“你怎么知道？”

学生：“第二题不需回答。”