VOA常速英语:Did Early Man Contribute to Central Africa Climate Change?

2. replace vt.取代, 代替
例句：Electric lights have replaced candles.
电灯已经取代了蜡烛。

3. dot vt. 分布各处; 布满；点缀
例句：The sky was dotted with stars.
天上繁星密布。

4. accumulate v. 堆积; 积累
例句：Snow accumulated on the ground.
地上积了一层雪。

5. deteriorate vi. 恶化, 变坏,退化
例句：Relations between the two countries have deteriorated sharply in recent weeks.
最近几周那两个国家间的关系严重恶化了。

6. weather v. 晒干; 风化
例句：The wind and sea have weathered the rocks quite smooth.
这些岩石因风和海水的作用变得非常光滑。

7. trigger vt.引发, 引起
例句：The incident triggered an armed clash.
这起事件触发了一场武装冲突。

8. alternate v. (使)交替, (使)轮换
例句：Day and night alternate.
昼夜更替。

9. evidence n. 证词; 证据; 迹象
例句：The room bore evidence of a struggle.
这房间里有搏斗过的迹象。

10. emission n. 排放,散发,发出(气体、光、热)
例句：The policy aims at cutting down exhaust emissions.
这项政策的目的是控制废气排放。