Please sit dowm.属于哪一类短语?例如过去时,现在时,现在进行时等等.强调是过去式，现在时和现在进行时中选一个

Please sit dowm.属于哪一类短语?例如过去时,现在时,现在进行时等等.强调是过去式，现在时和现在进行时中选一个 And this is my sister,Mary_____,JimSit dowm,please! Sit down,please. 英语Sit down,please, Sit down,please是什么意思 sit down,please答语? sit down please sit down please怎么回答 Sit down please用英语翻译 Sit down,please 怎么回答? please sit down的回答 Sit down,please翻译是什么 please sit down(写出反义词) sit down please的意思 sit down,please答句填什么? Please have a sit.改错 Please let t____ sit down. () in,please.sit() a borrowed dinner please