BBC news 2009-10-18 加文本

1.The fighting has made it almost impossible for locals to flee South Waziristan.

参考翻译：紧张的战斗使当地居民几乎不可能逃离瓦齐里斯坦南部。

语法学习：It is+adj.+of sb. +to do sth 与It is +adj.+for sb.+to do sth的区别。

It is+adj.+of sb. +to do sth中的adj.跟sb.有关,
这个adj.是用来形容sb.的,
表示某人这么做真是太adj.了．
你会发现在这个句型中你把sb.和adj.提出来可以造个句sb. is(are) adj.
如It‘s very kind of you to help me.
把里面的sb.和adj.提出来可以发现you are kind是说得通的.

而It is +adj.+for sb.+to do sth表示做某事对某人来说很adj.
这里的adj.是do sth.的属性
里面的sb.跟adj.没有直接联系
如It‘s difficult for you to deal with the problem.

2. Mr. Kerry said it would be entirely irresponsible to commit more troops to the country until its election crisis was resolved and the US knew exactly what kind of Afghan government it was working with.

参考翻译：John Kerry说，现在向阿富汗增派更多军队是完全不负责任的行为，除非其选举危机已经解决，美国政府完全知晓将与什么样的政府合作。

语法学习：till(up to):直到...时候（不能用于句子开头）

up till(up to )一直到（可用于句子开头） 

untill      除非到....时候

 not unitl（after）  在...之后

They didn't realize their fault till we pointed it out to them

直到我们向他们指出了他们的错误。（他们是否意识到了呢？没有说明，暗含意识到了。）

They didn't realize their fault until we pointed it out to them

直到我们向他们指出了他们的错误，他们才意识到。（他们确实意识到了）

Not unitl we pointed their fault out to them, did they realize it.

当我们指出他们的错误之后，他们认识到了自己的问题。

The students made much noise till the teacher came into the classroom .
直到老师走进教室学生们才停止了大声喧哗。 (强调延续到老师进来后，暗含进来后就停止了。)
The young couple were very happy until they used up all their money .
那对年青夫妇直到花光了所有的钱才沮丧起来。
另外，until 可以放在句首而till则不行。我们可以说：Until they used up all their money, the young couple were very happy .

我们却不可以说：Till they used up all their money, the young couple were very happy .

我们却可以说 Up till they used up all their money, the young couple were very happy . 

We've cooperated very well up till now.我们到目前合作很好（以后不知道）

They're here till Christmas. 他们在这里要一直逗留到圣诞节。（强调的是他们在圣诞节之前都在这里）
They're here until Christmas (圣诞节后他们就会离开）

Not until Christmas  did they leave for Beijing.(强调他们去北京了）

3. The Massachusetts Senator’s comments come at a time when the Afghan President Hamid Karzai resisted international pressure to accept fraud rulings that could force him into a runoff with his main rival, Abdullah Abdullah.

参考翻译：这位马萨诸塞州参议院发表评论之际，阿富汗总统卡尔扎伊拒绝国际社会要求其接受欺诈裁决，与主要竞争对手阿卜杜拉进行最后决定性竞选的压力。

结构分析：at a time when，when引导的是定语从句，修饰time。that could force him是定语从句，修饰fraud rulings。