如果我没记错的话，六点钟有一趟火车。

If I remember rightly , there's a train at six o'clock.

《牛津词典》

如果她对自己有一事而自豪，那就是她的公开及光明正大。

If there was one thing she prided herself on, it was being open and aboveboard.

《柯林斯英汉双解大词典》

如果你有一个树桩，就在上面找找菌类。

If you have a tree stump, check it for fungus.

《柯林斯英汉双解大词典》

Sometimes it's remarkable for all of us if we try to be very prepared-mind-oriented, very proactive around where the most interesting opportunities.

有的时侯,如果我们能时刻做好准备，积极地去寻找那些很有吸引力的机会,那将会是一件很了不起的事。

斯坦福公开课 - 扎克伯格谈Facebook创业过程课程节选

If our vision is truly realized MIT and there are open course not just in MIT but on every campus.

如果达到了这一目标,不仅在,其他学校也有开放课程。

麻省理工公开课 - 媒体、教育、市场课程节选

Think about that. That says, if this thing has some particular value, I want to do one thing; otherwise, I want to do something different.

考虑考虑，这意味着，如果这个事情有一些特殊的值，我就去做一件事情;,否则的话，我就会去做另外一件事情。

麻省理工公开课 - 计算机科学及编程导论课程节选