i have been sitting around waiting for the phone to ring all the day. 解释一下为什么have been+doing 而不+done 还有为什么wait要加ing

I had been sitting 和 I have been sitting 的区别多举些例子,并翻译 I have been sitting 的意思.,时态,相关句子-举例 一到初中的语法题,I ‘ve been sitting in front of the computer for an hour.I ‘ve been sitting能不能改成I have sit I have been sitting here for three hours.我在这坐了三小时.可否说成I sat here for three hours?也就是去掉have been,把 sitting改成过去式,意思是不是一样? i have been sitting around waiting for the phone to ring all the day. 解释一下为什么have been+doing 而不+done 还有为什么wait要加ing I sat at the table with Jwssica and her friends longer than I would have if I'd been sitting alone. I had been sitting的意思.,时态,相关句子-举例 I have been selling I have been trying I have ever been I too have been I have been to. I have been I have been in. How about my food?I___here for almost half an hour.A.have been sitting B.am sittingC.had been sitting D.was sitting I have been there,have been 是have been in还是have been to的缩写? i have always been there i have never been there I HAVE NEVER BEEN,能否说I never have been