VOA慢速英语:United States Fighting Operations in Iraq Officially End

不定式做表语

①不定式作表语一般表示具体动作，特别是表示将来的动作。如：

To do two things at a time is to do neither. 一次做两件事等于未做。

What I would suggest is to start work at once. 我的建议是立刻开始干。

②如果主语是不定式（表示条件），表语也是不定式（表示结果）。如：

To see is to believe. 百闻不如一见。

To work means to earn a living. 工作就是为了生活。

③如果主语是以aim，duty，hope，idea，happiness，job，plan，problem，thing，wish等为中心的名词，或以what引导的名词性从句，不定式作表语是对主语起补充说明作用。如：

His wish is to buy a luxurious car in the near future. 他的希望是在不远的将来买一辆豪华轿车。

2.One thousand Iraqi soldiers were to arrest suspected terrorists.

be to表示将来时

be to 表示客观安排或受人指示而做某事。
　　 be going to 表示主观的打算或计划。
　I am to play football tomorrow afternoon.　　 (客观安排)
　I'm going to play football tomorrow afternoon. (主观安排)

3.Elections held six months ago failed to produce a clear winner. For this reason, the country has yet to form a new government.

fail to未能…

例句：He failed to pass the test.
      他没有通过考试。

have yet to尚有待于，还没有

例句：Two major problems have yet to be addressed
      两个主要问题仍有待解决。