BBC news 2009-10-18 加文本

1.But the army is also pushing hard and air power is likely to play a decisive role. 

play a role起作用，role前面可以加形容词，表示发挥什么样的作用。相当于play a part.

例句：They played a shameful [ despicable ] role in this farce.
       他们在这一场闹剧中扮演了可耻[可鄙]的角色。

2.Those who managed to escape say they walked for over 24 hours to get out.

manage to达成, 设法，本身就含有successfully did sth的意思。

例句：Xiao Lin managed to accomplish her work in time.
      小林设法及时完成了任务。

3.Two Brazilian policemen were killed when their helicopter came under fire as they responded to an outbreak of violence in a shanty town in the city of Rio de Janeiro.

under fire遭到炮火射击,受到攻击

例句：The enemy retreated under our heavy artillery fire.
      敌人在我们的重炮轰击下撤退了。

表示起火的两个词组：

set on fire焚烧；纵火，引起点火或燃烧；使兴奋

例句：Some sparks from a passing train set the haystack on fire.
      一列过往火车迸发出的一些火花点着了干草堆。

set alight点燃,着火,使燃烧,开始燃烧

例句：A cigarette set the dry grass alight.
      香烟把干草点着了。

4.The police helicopter is believed to have crashed after the pilot was struck in the leg by a bullet and attempted to make an emergency landing on a football ground.

attempt to企图，是动词，做谓语

例句：He attempted to mediate their differences.
      他试图调停他们的分歧。

in an attempt to试图…,企图…，做状语

例句：The police fired in an attempt to disperse the crowd.
      警察开枪想驱散群众。