VOA慢速英语:G-20 Leaders Promise Steps to Avoid Currency War

1.Leaders from the Group of 20 urged "advanced economies" to guard against disorderly movements in exchange rates.

guard against避免, 预防

例句：We must guard against accidents.
      我们必须谨防事故。

The doctor must always guard against passing on disease to his family.
医生必须时常提防把疾病传染给他的家人。

2.Letting currencies reflect market fundamentals, allowing your currency to move up and down depending on the role that you're playing in the international trading system, is the best way to assure that everybody benefits from trade rather than just some.

depend on随…而定

例句：Whether the game will be played depends on the weather.
      比赛是否举行要看天气而定。
 
      It depends on the weather.
      那要看天气如何而定。

3.I stress a little while because as long as we have this very unbalanced global recovery we are going to get periodic tensions in policy setting.

as long as只要, 如果

例句：I'll stay in Mexico as long as my money holds on.
      只要我的钱还能维持一天, 我就在墨西哥待一天。