Question

it is 4:00 he and his brother are having fun (play) games 用所

Answer 1

答案：playing

have fun in doing sth.译为“开开心心做某事”.have fun意为“过得快活”,后常接动词－ing形式,其前的介词in可以省略.相当于enjoy oneself,have a good time.

have fun in doing sth.与have fun doing sth.相同,两者没什么区别,可以通用.