30. not only … but (also) 不但……而且(连接两个对等的主语，谓语，表语，宾语，不定式，ING结构，ED结构或分句)
We will not only bring joy into other people's lives, but also, very often, add happiness into our own. 我们不仅要给别人的生活带来欢乐，而且经常给我们自己的生活增添幸福。
12) Nature ［A］ not only gave the Middle Atlantic region fine harbors ［B］ , howerver ［C］ endowed it with ［D］ a firstclass system of inland waterways.
31. now that 既然(引导原因状语从句)
The Russians might come in a few hours and kill them all ——though most of them were already thinking of how they could escape——but in the meantime, for a brief spell, now that the Fuehrer's strict control of their lives was over, they would seek pleasure where and how they could find it.俄国人说不定几小时之内就要打进来，将他们统统杀掉——尽管他们中间大部分人已在考虑如何逃命——但此时此刻，既然元首对他们生活的严格控制已经结束，虽是短暂的片刻，他们也要及时行乐。
32. or else 否则；要不(就)(引导并列从句)
You must go there at once or else you can not be able to come back in time. 你心须马上就去，否则你就赶不回来了。
My brother couldn't concentrate upon his guide books for matriculation of postgraduate very long, he was too tired, ——or else too sleepy. 我弟弟不能集中精力看他的考研书，他太累了——要不就是太瞌睡了。
33. provided (=providing) 以……为条件，如果……的话，只要(引导条件状语从句，有时和that连用)
She could go with us provided that she arrives in time. 她如及时赶到，就会和我们一起去。
I'll go to the U.S.A, provided I have enough money. 只要我有足够的钱我就去美国。
注：provided在正式文体中用得更多。
34. since 自从；因为(引导时间和原因状语从句)
It has been only forty years since television came to control American free time. 电视开始主宰美国人的空闲时间，至今也不过才40年。
Prof. Glom has named them skyscrapers since they seem to be scraping the skies. 格莱姆教授将它们命名为摩天大楼，因为它们似乎已经擦到了天。
It was 3:30 PM on Monday, April 30, 1945, ten days after Adolf Hitler's fiftysixth birthday, and twelve years and three months to the day since he had become Chancellor of Germany and had instituted the Third Reich. 当时是1945年4月30日星期一下午3点30分，是他56岁生日的第10天，离他当上德国总理和成立第三帝国正好12年零3个月。