| 1. | Insects need an external source of sterols . 昆虫需要外界来源的固醇类。 |
| 2. | What is the origin of pelagic oozes ? 远洋软泥的来源是什么? |
| 3. | He has secret channels of information . 他有秘密的消息来源。 |
| 4. | Heat gain may come from the following sources . 热量的增加可能有下列一些来源。 |
| 5. | Urban areas have depended on local sources of food . 城市地区都依靠当地的粮食来源。 |
| 6. | He is sometimes slipshod in handling his sources . 他在处理资料来源时有时有点潦草。 |
| 7. | He was averse to revealing the sources of his information . 他不乐意透露消息的来源。 |
| 8. | They are undesirable sources of their contained metals . 它们不是所含金属的理想来源。 |
| 9. | Fish oil is a particularly potent source for vitamin a . 鱼肝油是维生素A特别有效的来源。 |
| 10. | Peasants therefore have no source of external income . 结果农民丧失了任何其它的收入来源。 |