1. These are migrant birds.
    这些鸟是候鸟。

2. These birds migrate to North Africa in winter.
    这些鸟冬天迁徙到北非.

3. The birds are busy building their nests.
    鸟儿正忙着筑它们的巢.

4. The birds are silent in the trees.
    鸟在树上悄然无声。

5. The birds start to sing at sunrise.
    鸟儿在黎明时开始歌唱。

6. There are also endless numbers of birds in the tar as well.
    沥青坑里还有无数只鸟的尸体。

7. No two sorts of birds practise quite the same sort of flight; the varieties are infinite;
    没有两种鸟的飞行方式完全相同, 其差异是无穷的.

8. No two sorts of birds practise quite the same sort of flight;
    没有任何两种鸟的飞行方式是相同的。

9. Nothing can be compared, he maintains, with the first cockcrow, the twittering of birds at dawn, the sight of the rising sun glinting on the trees and pastures.
    他坚持认为，凌晨雄鸡第一声啼叫，黎明时分小鸟吱喳欢叫，冉冉升起的朝阳染红树木、牧场，此番美景无与伦比。

10. Kill two birds with one stone.
    一石双鸟。