walking dogs is not allowed 为什么用is 不用are?

题目

walking dogs is not allowed 为什么用is 不用are?
When water freezes,it turns into ice.The underline part means( )A gets into
B becomes into      C comes into   Dchanges into

答案

Walking dogs is not allowed 为什么用is 不用are?
此句不是dogs做主语,而是Walking dogs动名词短语做主语,动名词短语做主语,谓语动词用单数形式.
句意是：“不允许遛狗”.
When water freezes,it turns into ice.The underline part means( )
A gets into B becomes into C comes into D.changes into
选项是D
turns into =changes into