1. But optimists see the current problems of expanding cities as merely part of an evolutionary process.
    但是乐观主义者认为，现在城市膨胀造成的问题只不过是发展过程中的自然现象。

2. But can the colossal cities of the future really function without overloading all their services to the point of collapse and destroying the environment through pollution of air and water?
    但未来的巨城真的能够正常活动，而不会使城市的一切公共设施因超负荷而崩溃、不会由于空气和水的污染而使环境受到破坏吗？

3. But I did not know that the sun could shine and the air remain cold; no one had ever told me.
    但我不知道阳光灿烂时，空气还会是冰冷的，从来没有人告诉过我这一点。

4. But then Sam lets go of the swing. He flies into the air and lands face down in the dirt.
    但就在此时，山姆从秋千上飞了出去，脸朝下摔在地上。

5. By measuring how closely current populations are related, the authors trace the routes by which early humans migrated around the earth.
    通过测定当前人类种群间的亲缘关系，作者们弄清了地球上早期人类迁移的路线。

6. We were rowing against the current.
    我们逆水划船.

7. We couldn´t induce the old lady to travel by air.
    我们无法劝说那位老太太坐飞机去.

8. When farmer spray poison to kill plant pests, poison is sent into the air the water and the soil.
    农民为了杀死害虫而喷撒农药的时候,有毒物就被排放到空气中, 水里和土壤里.

9. Wires transmit an electric current.
    电线传导电流.

10. Will you venture a flight in an air plane?
    你敢坐飞机飞行吗？