正确答案：
1、I have a baseball.
一般问句：Do you have a baseball?
否定回答：No,I don't.
2、She likes playing ping-pong.
一般问句：Does she like playing ping-pong?
否定回答：No,she doesn't.
3、They play sports every day.
一般问句：Do they play sports every day?
否定回答：No,they don't.
解析：这3句都是不含有be动词的情况,我们改为一般疑问句只要提前相应的助动词,注意人称的变换就行,最后注意动词的还原.这样讲懂了吗?