However,it was not until World War II that two other scientists,Howard Florey and Ernst Chain,managed to use new chemical techniques to purify it.然而,直到二战期间,另外两个科学家Howard Florey 和 Ernst Chain 才用新的化学技术设法把它纯净。 含有not...until...的强调句型: 其强调句型结构为:It is/was not until+被强调部分+that+其他句子成分。 I didn’t realize she was a famous film star until/till she took off her dark glasses. →It was not until she took off her dark glasses that I realized she was a famous film star. 直到她摘下墨镜,我才意识到她是位著名的影星。 27.(2008年重庆卷)It was not until midnight________they reached the camp site. A.that B.when C.while D.as 【解析】 句意为:直到午夜他们才到达营地。it was not until...that...强调句结构。 【答案】 A 28.(2004年湖北卷)It was________back home after the experiment. A.not until midnight did he go B.until midnight that he didn’t go C.not until midnight that he went D.until midnight when didn’t go 【解析】 句意为:直到午夜他才做完实验回家。it was not until...that...强调句结构。 【答案】 C It was over a decade before someone else turned penicillin into the great drug of the 20th century.十年之后其他科学家才把盘尼西林变成了20世纪伟大的药品。 It is/was/will some time before...表“多久之后才……”。 该句型主句中be动词的时态常是一般将来时或过去时两种时态,主句中的表语多是long,not long,days,weeks 等表示时间段的词或短语。 It will be not long before we meet again. 不久我们就会再见面的。 It will be some time before we know the full results. 再过些时候我们才能知道全部结果。 |