look what a nice classroom it is yes ,lt is cleaned every day .为什么是 is cleaned
问题描述：
look what a nice classroom it is yes ,lt is cleaned every day .为什么是 is cleaned
答
这里的clean是动词打扫的意思
因为正在对话,所以用一般时的is
be动词后加动词,用动词的过去分词形式
所以是is cleaned