at this time ,by this time 有什么区别么?意思是什么?

by this time、by that time、at this（that?） time、since then 的区别 this time by this at this time ,by this time 有什么区别么?意思是什么? in this time还是at this time? at this time 与at this point at this time of day 改被动语态He was doing his homework at this time yesterday .He was doing his homework at this time yesterday .--His homework was being done by him at this time yesterday ...为什么不能改成His homework was done by him at this time yesterday The Englishman,who was very hungry by this time and not at all thirsty.局中by是否可以用at代替?请说明理由. 1.I read the book written by Lu Xun last summer.（用at this time yesterday改写句子）I ______ _______ the book written by Lu Xun at this time yesterday. the englishman,who was very hungry by this time and not at all thirsty.请问这句话跟the englishan was very hungry by this time and not at all thirsty.有什么不同?为什么要用上一种方式表达? at this time 与 in this time 有什么区别? at that time与at this time的区别 at that moment ；at this moment ；at this time ；at that time分别用什么时态? I just caught the first bus ( ) time this morning?A.in B.on C.at D.by there is always a lot of t( ) at this time of day.you 'd better go by bike. I got this job completely by chance ——I was in the right place at the right time 急.解释几个英语短句.1.at times2.at this time3.at the same time4.by the time要求翻译成中文, at this time at this point两者意思一样么?