This was the real reason for her call.

这是她打电话的真实原因。

《柯林斯英汉双解大词典》

As always, Peter had a reason for his action.

如往常一样，彼得对他的行为总有理由。

《柯林斯英汉双解大词典》

I have no particular reason for doubting him.

我没有什么特别的理由怀疑他。

《牛津词典》

The report says one reason for the growing deadliness of cancer is more people smoking cigarettes in developing countries.

VOA: special.2009.01.13

Now, there's an important reason for this genealogy, the idea that the muses are the daughter of Mnemosyne, the goddess of memory.

现在，对于这个宗谱有一个重要的解释，即缪斯女神们是记忆之神摩涅莫辛涅，的女儿。

耶鲁公开课 - 弥尔顿课程节选

What do you think is the reason for San Francisco being such a diverse place with people from all around the world?

为什么旧金山能聚集全世界各个地方的人呢？

移民者的都市 - SpeakingMax英语口语达人

One reason for this separation of services is because the two are charged for differently.

BBC: Graphic

And seven in 10 say Bush's overall job performance was the reason for the Democratic victory.

NPR: The Issue of Iraq Policy Change Takes Hold in Washington

Kentucky that prosecutors have to have a good reason for striking a black or Hispanic or Asian juror.

NPR: Slate's Jurisprudence: Court Passes on Padilla Case