I ( ) writing a letter to Mary 填空括号里填 am 还是 is 还是 are快

I'm writing a letter I am writing a letter是什么意思 I‘m writing a letter.改成问句 I am not writing a letter.改错、 I am writing a letter.提问： I not writing a letter.改错 I am writing a letter.这里的writing是及物动词还是动名词啊? I'm writing a letter 改为特殊疑问句 i have some writing paper an a envelope 怎么改错 Am I writing a letter?的反义疑问句是什么? 现在完成进行时态与现在进行时态的区别是什么?例如i have been writing a letter和i am writing a letter例如i have been writing a letter和i am writing a letter有什么区别 a,letter,was,just,i,now,writing怎么写 I am writing a letter you in my school为什么 writing,my,i,a,father,letter,to,am 排句 I am busy writing a novel.是什么句型 I am writing a report now.改为一般疑问句 a,letter,was,just,i,now,writing怎么写 I don't have any( ) writing a note in English