1 . These trees, which ____________________, were cut down.  
三年前栽的这些树被砍倒了。

2 . …extinct every year. This ________________. We must…(根据句意填空)

3 . 普遍认为，健康的饮食首先由有一个对食物健康的态度开始。(It作形式主语的主语从句)
It is ______ .

4 . She ________ if she hadn’t allowed herself some fun.
她若是没给自己找点乐趣的话，早就崩溃了。

5 . The first time I met Jane, we talked a lot about study ________.
第一次和简见面，我们就谈了很多关于学习的事，就好像是老朋友一样。

6 . He stared at me ________.
他瞪着我看，好像我犯错了一样。

7 . ___ need not be right for others.  
对我们来说是对的东西, 对别人来说未必正确。

8 . The little boy _______ (深吸一口气) and _______ (屏住呼吸) before he got into the water. After a moment, he put his head out of the water. It seemed as if he was _______ (喘不过气), but soon he _______ (正常呼吸) again.(根据汉语提示完成句子)

9 . When Barry finished building Highclere in 1842, the castle had more than 50 rooms, including one room with ______ ______ ______! But this room was only used ______ ______ ______. Today, Highclere is one of the most expensive houses in Britain, worth more than 150 million pounds. (根据句意填空)

10 . 就是在雨林里我欣赏到了独特的动植物。
It was ______ ______ ______ ______ I admired the unique plants and animals.