often it's the delivery which causes the audience to smile, so speak slowly and remember that a raised eyebrow or an unbelieving look may help to show that you are making a light-hearted remark.
常常是你说话的方式使听众发笑,因此说慢一些,并且记住扬扬眉毛或者做出一种不相信的表情都会向人们显示你正在说笑话。