Complete the sentences. 1. A bad thing can be ______ ______ a good one. 坏事可以变成好事。 2. We can ______ to buy a house between us. 我们有能力合买一所房子。 3. The international situation is extremely ______ . 国际形势极为严峻。 4. He felt the press of ______ life. 他感觉到现代生活的压力。 5. The computer contains a large number of ______ switches. 计算机内包含大量电子开关。 6. ______ paper bags have been developed. 一种用后即可废弃的纸袋被设计出来了。 7. About half the chemical ______ have checked out. 大约有一半化学工程师已经退房。 8. A nuclear reactor ______ tremendous amounts of heat . 一座核反应堆能发出巨大的热量。 9. The news ______ all of us. 这新闻引起了大家的兴趣。 10. The boy is ______ about everything. 这个男孩对任何事情都很好奇。 11. He is engaged in ______ research. 他从事科研工作。 12. How did you reach that ______ ? 你怎么得出那个结论的? 13. Several ______ problems must be overcome. 有几个实际问题必须予以解决。 14. New york has always been a ______ community. 纽约一向是商业性的社会。 15. Hard work always takes your mind off ______ problems. 工作一劳累就使人不再想着家庭问题了。