| 11. | At the time when technology means ever more harmful carbon in the air we breathe, we need these forests now more than ever. |
| 术的发展意味着我们会吸入更多有害气体时，我们比任何时候更需要森林。
|
| 12. | Soft drinks contain carbon dioxide. |
| 软饮料中含有二氧化碳。
|
| 13. | The secretary kept a carbon of each letter she typed. |
| 秘书把她所打的每一封信都保留一份副本。
|
| 14. | Please make a carbon of that report. |
| 请把那份报告制一个副本。
|
| 15. | The typist put a carbon between the sheets of paper to make two copies of the letter. |
| 打字员在两张本之间夹入一张复写纸，以便把信打成一式两份。
|
| 16. | carbon monoxide |
| 一氧化碳
|
| 17. | make a carbon copy of a document |
| 用复写纸复写一文件
|
| 18. | weak acid made by dissolving carbon dioxide in water |
| 碳酸
|
| 19. | carbon dioxide |
| 二氧化碳
|
| 20. | carbon black |
| 墨黑，漆黑
|