Scientists have many theories about how the universe _______ into beingA.came B.was coming C.had come D.would come请详细解释下BCD为什么不选?

Scientists have given many ideas for ______space. 初三英语第八单元的词汇- -首字母填空Scientists have given many ideas for ______space. Scientists have many theorise about how the universe ____ into being Many scientists have ____(aready,yet)been to the North Pole.填什么 Many scientists have created a new t____ to diagMany scientists have created a new t____ to diagnose and treat children born with heart disease. 这句英语句子可以改成这样吗When the cloning technology improves so quickly,many scientists and doctors have different opinions改成 The cloning technology improving so quickly,many scientists and doctors have different opinions Scientists have many theories about how the universe ______into being.括号里填had come 还是came.为什么? Scientists have many theories about how the universe first came into existence帮忙翻译下这句话,谢 Many leading scientists down through the years from Galileo to Einstein have been deeply religious.这句话应该如何翻译 scientists have many the ories about how the universe ---into beinga came b was coming chad come d would come Scientists have many theoyies about how the universe_____into being.A.came B.was coming c.had come D.would come many of the ideas which scientists tell us have no foundation have to do with mixtures of foodswhich have no foundation是us的直接宾语从句?scientists tell us是idea的定语从句? many scientists are again becoming excited--- The scientists have tried____times,but they still don't have any information about the UFO.用many，much，fuw或little填空 Scientists have many theories about how the universe into being.A. came B. was coming C. had come D. would come Scientists have many theories about how the universe _______ into being 为什么此处要用was coming 而不用would come最好具体一些 Scientists have many theories about how the universe _______ into being .A.came B.was coming C.had为什么选A Scientists found many stones --- with number on the mountains.A.marking B.marked C.being markedD.have been marked选B ,why?