The experiment shows that high efficiency, fast and damage-free charge is realized by this device.

实验表明，该装置真正体现了高效、快速、无损害的充电思想。

youdao

Delivery is free of charge.

免费送货。

《牛津词典》

Tickets are available free of charge from the school.

学校有免费票。

《牛津词典》

Question Box is a service that provides answers free of charge for people who cannot search the Internet directly.

VOA: special.2009.10.12

We, in fact, borrow oxygen or steal oxygen from the air free of charge.

我们事实上免费从空气中,借或者偷氧气。

麻省理工公开课 - 固态化学导论课程节选

where we could have dinner and it was free of charge, that kind of thing.

我们可以在那里吃晚餐，而且完全免费，诸如此类的。

请支持一下社团小组 - SpeakingMax英语口语达人

US. Since TellMe, like its competitors, is free of charge, these calls are also free.

ECONOMIST: Internet

Any publisher or distributor who chose not to sign the agreement is free to charge whatever it wants for ebooks, and any consumer is free not to buy from those who did sign.

FORBES: 3 Things Everyone Needs to Know About the Apple Antitrust Case

Lawyers say the signs in the lobby listing the price of admission with the word "recommended" below in smaller type violate a 1893 law mandating the public be admitted free of charge at least five days and two evenings per week in exchange for monetary grants and rent-free use of city-owned land.

BBC: Metropolitan Museum of Art's entrance fee 'deceptive'