4.　 human activity 人类活动

3.　 depend on 依靠

2.　 a supply of /supplies of 大量的

1.　 global warming 全球气候变暖

8. It is only when the disease has progressed to AIDS that a person begins to look sick.

只有当这种病毒发长成艾滋病时，人才会显出病态。

Unit 4 Global warming

7. You can have HIV in your blood for a long time, but eventually it damages your immune system so much that your body can no longer fight disease.

在你的血液里，HIV病毒可以长期存在，但是它最终会使你的免疫系统严重受 损，以至使你的身体不再能抵抗疾病。

6. I do hope so because I want you to live as long and healthy a life as I live.

我的确希望这样，以为我想让你过上和我一样长寿而又健康的生活。

5. I also noticed that I couldn’t run as fast any more and I wasn’t enjoying sport as much..

我同时也意识到我不能再和以前跑得一样快乐，而且我也不那么喜欢运动。

4. I didn’t know it could do terrible damage to your heart and lungs or that it was more difficult for smoking couples to become pregnant.

我不知道抽烟会严重损害人的心脏和肺，也不知道吸烟的夫妇的生育能力会下降。

3. As you know, if you do the same thing over and over again you begin to do it automatically.

正如你所知道的，如果你反复的做同一件事情，你就会开始机械的地做它。