I went out for teeth( clean ) just now 括号里的单词按sh形式填空

题目

I went out for teeth( clean ) just now 括号里的单词按sh形式填空
I went out for teeth( clean ) just now 括号里的单词按什么形式填

答案

答案：cleaning
for为介词,其后如果加动词,则一般使用其动名词形式.