BBC news 2011-01-22 加文本

contribute to促成

例句：Smoking is a major factor contribute to cancer.
      吸烟是致癌的一个重要因素。

2.Several street demonstrations have taken place in the Albanian capital since the 2009 disputed election, but this is the only one which has descended into such chaotic scenes.

descend into落进，变成，沦落成

例句：You descend slowly down into the darkness.
      你慢慢地下潜到一片黑暗之中。

3.A group of soldiers then took revenge on the people of Fizi.

take revenge on向…报仇,对…进行报复

例句：Hurt oneself in trying to take revenge on sb else
      想报复别人而害了自己

4.President Laura Chinchilla Miranda told the BBC Nicaragua should concentrate on improving the lives of its citizens instead of occupying Costa Rican territory.

concentrate on专心于, 把思想集中于

例句：Many firms are concentrating on increasing their markets overseas.
      许多公司正在集中精力开拓它们的海外市场。

      I wish you'd concentrate on what I'm saying.
      但愿你能集中注意力听我讲。