美国的部落人口

2. lure vt.吸引, 引诱, 诱惑
例句：The price also lures students.
这种价格对学生也有吸引力。

3. strain vt. 使(物资)耗尽，使紧张
例句：The supply of oil has been strained.
石油供给几乎到了危机的边缘。

4. witness vt. 亲眼看见, 目击；见证
例句：I witnessed the accident.
我亲眼目睹了这场事故。

5. spate n. 大量,许多
例句：Doctors have suffered a loss of prestige following a spate of scandals.
接二连三的丑闻使医生名誉扫地。

6. exclude vt.排除; 不包括在内
例句：The club excluded women from membership.
该俱乐部拒绝妇女入会。

7. relinquish vt.交出, 让给；放弃
例句：He was forced to relinquish control of the company.
他被迫放弃公司的掌控权。

8. dilute vt. 使减低(效果)，减轻，削弱
例句：The professor's proposals were diluted by the lack of support from his department.
该教授的建议因缺乏系里的支持而不被重视。

9. stagnate vi.停滞, 不流动, 不发展
例句：The war stagnated researches into the causes of cancer.
那场战争使癌症起因的研究工作停滞不前。

10. descent n. 世系,血统
例句：Many Americans are of English descent.
许多美国人有英国血统。