改为否定句（英语的）
问题描述：
改为否定句（英语的）
This is a computer game .(改为否定句） He is 13 years old .(对13years old提问） Is this your pencil (做出肯定回答)
答
1.This isn't a computer game.( isn't = is not )
2.How old is he?
3.Yes,it is.