英语单词understand,我一直以为是句子Are you stand?

英语单词understand,我一直以为是句子Are you stand? 英语单词understand,和句子Are you stand.是同一个意思吗 “你明白吗?”用英语是Are you stand?还是Do you understand? You are to stand here.Do you understand?You must stand here. 是Are you stand吗? 是are youunderstand?还是do you understand? 英语翻译句子是when you are crossing a road,stand well back from the “Are you stand”是什么意思? Are you understand are you understand 还是do you understand 英语单词怎么拼句子我会英语单词`可是就是不知道拼成句子`比如：What are you doing是怎么拼法的 明白了吗?是Are you stand? 还是Do you under stand?