单项选择题

Questions 19 to 22 are based on the conversation you have just heard.

A．The purpose of laughter.
B．The cause of laughter and its effects.
C．Why and when people laugh.
D．The origin of laughter.

<上一题目录下一题>

热门试题

单项选择题

问答题

1. 人生中竞争很重要 2. 然而，合作也很重要 3. 我的看法

Questions 19 to 22 are based on the conversation you have just heard. 您的浏览器不支持 audio 元素。