I want to know how long () A.has he been back B.has he been back C.he has been back该选哪个?不好意思，输错了。B答案是has he come back参考答案是A 但我觉得是C 请问到底该选什么呢？

I want to know how you I want you to know more how much I love How do i live without you ,i want to know. i want to know how should i do要中文 I want to know how to get there.改为复合句 I want to know how to eat and drink_____(health) I just want to know how much you love I want to know how ()(learn)English well. I want to know how you like like--怎么翻译 i want to know how the dish tastes good翻译 i want to know how much does it costi want to know how much it costs 哪个是对的 改为同义句.I want to know how I can study English well.I want to know () () study English well. I am unhappy,i don't know how to do?i want to leave here. 我想知道如何算出这道数学题. L want to know how to ___ ___ the Maths problem. I don't know how to be happy?Want to ask I don't know how to be happy?Want to ask you I really want to know how sb is 是填how还是what I really want to know how sb is 是填how还是what How many planets in the Universe?I want to know how many planets in the Universe.