The table folds up when not in use.

这桌子不用时可以折叠起来。

《牛津词典》

Use the active voice when writing sentences.

造句时使用积极的语气。

youdao

The language and style you use when making an oral presentation should not be the same as the language and style you use when writing.

你在做口头报告时使用的语言和风格与你书写时用的不同。

youdao

Automatic faucets use an electronic sensor to start and stop the flow of water when people wash their hands.

VOA: special.2011.04.06

>> They only use that when the program that you're running-- the program that you're referring to is going to your computer?

>它只有在你运行程序的时候才用到-,那你刚刚提到的程序,会到你的电脑上运行吗？

哈佛公开课 - 计算机科学课程节选

We usually use this pattern when the question that you're asking about relates directly to the person you're speaking with.

当你在询问与谈话对方直接有关的话题时，你可以使用这个句型。

Do you 课堂 - SpeakingMax英语口语达人

"You are getting the very best exchange rate when you use the credit card as opposed to cashing traveler's checks or cash, " he said.

CNN: Conquer the currency conversion conundrum

Today it looks classic, in much the same way that such masterpieces of midcentury modernism as, say, Mies van der Rohe's Seagram Building or Frank Lloyd Wright's Guggenheim long ago ceased to look "modern, " at least in the informal sense that most people have in mind when they use the word.

WSJ: Long After the Initial Shock, Modernism Still Delivers | Sightings by Terry Teachout

Not least, Bezos himself noted that the company wants to make money mostly when Kindle buyers use the device, not when they buy it.

FORBES: *Updated below.