| 1. | Polyhedra with seven vertices are rare . 具有七个顶点的多面体是稀少的。 |
| 2. | Seven sovereigns had occupied the throne of england . 英国已有七个国王登过宝座。 |
| 3. | These huge macromolecules are of seven major types . 这些巨大分子有七个主要类型。 |
| 4. | Six men have been trapped in a mine for seventeen hours . 六个人困在矿井里已达十七个小时之久。 |
| 5. | This man had wasted seven of the best years of her life . 这个男人虚掷了她生命中最珍贵的七个年头。 |
| 6. | Halogen atoms contain seven electrons in their valence shell . 卤原子在它们的介电子层含有七个电子。 |
| 7. | The romance blossomed for six or seven months, and then wilted . 那罗曼史持续六七个月之后就告吹了。 |
| 8. | It begets at least seven standard type offspring from such matings . 这类交配中生下至少七个标准型后代。 |
| 9. | Fifty-seven irregular verbs have i introduced to my brain in the past four days . 过去四天里我背了五十七个不规则动词。 |
| 10. | Isolable carbocyclic compounds contain seven or fewer carbons in the cycle . 可分离的碳环化合物环内含七个或七个以下的碳。 |