1. Do you want a single or a return ticket?
    你要单程票还是往返票?

2. And if a single curved glass would distort nature, how much more would a pair of them?
    何况一片曲面镜就可歪曲自然，那么伽利略的两片曲面镜对自然的歪曲又该多大呢？

3. During a single crucial three-week period during our teenage years, chemical activity in the brain is cut in half.
    我们的青少年阶段有一个为期三周的关键时期，此时脑部的化学反应活动一分为二。

4. A single spark can start a prairie fire.
    星星之火, 可以燎原。

5. As a single man he had never troubled much if he happened to be out of work; but now that he was married it was different: the fear of being "out" haunted him all the time.
    他过单身生活时，即使偶尔失了业，他也未太烦恼过。可是，既然结了婚，情况就不同了，失业的恐惧时刻都在困扰着他。

6. As we drove along, someone would single out to me a famous building, an important street, a park, a bridge that when built was thought to be a landmark.
    当我们驱车行驶的时候，有人指给我看那些建造时被曾认为是陆上的标志性建筑物：著名大楼、重要街道，公园和大桥。

7. "The movements are very slow and careful and involve a great deal of body movement and standing on a single limb.
    它的动作缓慢、细腻，动则牵引全身，立则依附单腿。

8. A single tree may seem large compared to a person.
    和人相比，一棵树看起来很大。

9. An immediate search over 100,000 square miles of sea failed to turn up a single piece of the missing plane.
    随后立即展开了范围宽达100,000平方英里的海面搜索，但没有发现一片失踪飞机的残骸。

10. And while these industries are pioneering the most exciting new technologies, some critics fear that profit-minded companies will only develop services for the wealthy.
    尽管这些企业在最令人振奋的新技术上领先，一些批评者仍担心追逐利润的企业会只开发面向富人的服务项目。