题目内容：

Two fathers and two sons go to take a picture.When they see the photo,ther are three men on the picture.Why?(You can answer in Chinese.)_____________.(用英语回答）

优质解答

Because there is a father,a son and a grandfather.
因为一个是爷爷,一个是爸爸,一个是儿子.
所以,爸爸既是儿子,又是父亲.