A,there is a computer on the desk改为否定句是什么?一般问句是什么?肯定,否定回答是什么

原句 There are some studeuts on the playground.
反问 Are there any students on the playgruand?
否定 There are not any shudents on the playgruand.
问 Yes,there are.
答 No,there aren`t.
另一个句子只用将 are 改成is 而a computer on the desk 不变
再问： 谁是最佳答案呢。。哦