1. By the end of the next century, a single city may have more than 100 million inhabitants.
    到下个世纪末，一个城市的居民就可能超过一亿。

2. Behold her, single in the field,
    看她，一个人在原野上，

3. But there were times when not a single piece of dry wood could be found and even Humboldt lay with his eyes wide open, listening to the roars of the beasts that surrounded them.
    但也有一块干木也找不到的时候，就连洪堡也睁大了眼睛躺在那里，听着包围他们的野兽的吼叫。

4. Before all the different types of Barbie dolls for sale now, there was just a single Barbie.
    在现今各式各样的芭比娃娃出售之前，原只有一种芭比娃娃。

5. But a single optical fiber with a diameter of less than half a millimeter can carry more information than a large cable made of copper wires.
    但是单单一根直径小于半毫米的光纤电缆就可以比由铜丝制成的粗电缆负载更多的信息。

6. They had a single aim, a solitary goal-the top!
    他们有一个目的, 唯一的目标就是登上顶峰.

7. The only way that they can preserve their history is to recount it as sagas----legends handed down from one generation of storytellers to another.
    他们保存历史的唯一办法是将历史当作传说讲述，由讲述人一代接一代地将史实描述为传奇故事口传下来。

8. They had a single aim, a solitary goal----the top!
    他们只有一个目标，唯一的目标 -- 顶峰！

9. The first essential in elephant training is to assign to the animal a single mahout who will be entirely responsible for the job.
    驯象中至关生要的是指派一名专门的驯象员，全面负责这项工作。

10. The life history of the individual is first and foremost an accommodation to the patterns and standards traditionally handed down in his community.
    个人的生活史首先是适应他的社团世代相传形成的生活方式和准则。