BBC在线收听下载:白宫称奥巴马将访问尼日利亚

词汇讲解：

1. treat v.对待; 治疗; 处理; 款待 
例句：I'll treat you to lunch. 
我请你吃午饭。 

2. prevent vt.预防; 阻碍
例句：He has determined that nothing will prevent him. 
他已决心不顾一切阻碍。 

3. defend vt. 辩护; 保卫
例句：We must defend our country. 
我们必须保卫我们的国家。 

4. offend vt.触怒; 得罪，冒犯
例句：They were careful not to offend his nibs. 
他们小心翼翼，不敢冒犯这位大人。 

5. assistant n.助手，助理
例句：He chose George as his assistant. 
他选择乔治做他的助手。 

6. dismiss vt.解雇
例句：In consequence of his bad work, I was forced to dismiss him. 
由于他工作表现不好,我只好把他辞退。 

7. choose vt.挑选; 认为…比其它更可取
例句：I choose my acquaintances for their good characters. 
我挑选品格好的人与之交往。