i have been teaching since 2006中的teach为什么要加ing?

I have been teaching in this school since three years ago.变同一句.速求、、 英语翻译English,teaching,for,been,fire,have,years,I连词成句 I have been teaching English since 1986.改为同义句帮帮忙 i have been teaching since 2006中的teach为什么要加ing? 英语-请问这两句话有区别吗?i have specialized in teaching math for five years.i have been specialized in teaching math for five years. 1.I have been teaching in this school since 1998.(用for改写句子)I have been teaching in this school( )( )( ).2.The workers have been working for eight hours.(改为一般疑问句)( )the workers( )( )for eight hours? I have been teaching English in China for 5 years 与I have taught English in China for 5 yearsI have been teaching English in China for 5 years I have taught English in China for 5 years分别 英语改错：I am a English teacher.I have been teaching English for more than ten year. 1. I have been teaching English in China ___since I came to Beijing in 2005___(就画线部分提问) I [ ] in the school since I graduated from my college. I really enjoy my teaching .A, have been teaching B , taught C, have been taught [请说明原因,谢谢】 where have you been?we have been looking for you everywhere.i(worked out)a teaching plan in my office.为什么这里不填have been working out.had been working out; had been work out 这个英语错在哪儿i have been teaching here for 30 years when you graduate from this university i have no experiences in teaching English还是i have no experience in teaching English I have been selling I have been trying I have ever been I too have been I have been to.