这是一个二择其一的问题。

This is a binary decision.

youdao

正如那首歌所唱的，二者你不能只取其一。

You can't have one without the other, as the song says.

《柯林斯英汉双解大词典》

俄罗斯正在拆除其一些最具杀伤力的导弹。

Russia is deactivating some of its deadliest missiles.

《柯林斯英汉双解大词典》

Well, there are two reasons, one because I want you to hear literary art.

有两个原因，其一，因为我希望你们能听到文学的艺术。

耶鲁公开课 - 1945年后的美国小说课程节选

So, in particular, the new things here, two things, one the number of candidates is not fixed.

特别的,新的东西,有两个,其一是候选人的数目不固定

耶鲁公开课 - 博弈论课程节选

One is, in 1988 home prices were rising rapidly in Los Angeles, not so in Milwaukee, so people were just extrapolating the price increase.

其一,1988年,洛杉矶房价上升的势头很猛,密尔沃基却没有,所以人们推测房价会继续上涨

耶鲁公开课 - 金融市场课程节选