VOA慢速英语:Ebola Forces Sierra Leone Students to Learn by Radio

词汇讲解：

1. broadcast vt.广播; 播放
例句：The concert was broadcast by relay. 
这场音乐会是实况转播的。 

2. involve vt.包含; 使参与，牵涉
例句：The guidelines involve only microeconomic reforms.
指导方针仅仅包含微观经济改革。

3. protect vt.保护，保卫
例句：Game laws protect wild life. 
狩猎法保护野生动物。 

4. present vt.介绍; 出现
例句：A vivid picture was present to his mind. 
一幅生动的画面出现在他的脑海里。 

5. electricity n.电力; 电流
例句：This machine goes by electricity. 
这台机器是由电力推动的。