be believed to have done

be believed to have done be believed to 什么意思? He is believed to have done Jane made what ----the first known study of sea life.A believed to have been B is beileved to be The book _____ by a famous writer.A.believed to writeB.was believed to writeC.believed to be writtenD.was believed to be written be believed 后面必须加to吗?是固定搭配吗be believed to do sth He is believed to have left to London last friday. he was believed to have stolen it 为什么有was,believed是怎么回事,是什么时态 The flu is believed ______byviruses that like to reproduce in the cells insA.causing B.being caused C.to be caused D.to have causedwhy? The picture is believed ____ painted by tomA being B to be C to being D to have been 【 需要有解释.】 this picture is believed 填空 painted by Turner A it was B to be C to being D to have been求详解 THE BOOK__BY A FAMOUS WRITER.A:WAS BELIEVED TO WRITE B:BELIEVED TO BE WRITTENC:WAS BELIEVED TO BE WRITTEN D:BELIEVE TO WRITE be believed to 是据说的意思吗? It is believed to be是什意思? too unlikely to be true or believed什么意思 Tom is believed _____ handsome when he was in college.A.to be B.to have been C.having been D.being This kind of disease is believed ____by a virus.A.causing B.to be caused C.to have caused D.caused. The book ( )by a famous writer.选择[a] was believed to write [b]believed to be written[c]was believed to be written[d]believed to write请说明理由为什么选它