This was not a statistically controlled study: the subjects took a free test online and of their own accord.

这不是一个统计控制的研究：参与者自发地在网上做免费测试。

youdao

Instead, they expect to make a free test kit available on the Internet later this month to foster longevity research.

相反，他们想本月晚些时候在互联网上推出一项免费的长寿基因检测服务，以推动长寿研究。

youdao

Our consulting rooms have been facilitated with computers, so that you can also take a free test on your English level there.

咨询室内配有电脑，您可以在了解课程的同时获得免费测试英语能力的机会。

youdao

"If you have the opportunity to get tested for HIV, and there are so many different places that you can test for free, why wouldn't someone want to find out more information about their health."

VOA: standard.2010.07.23

The woman at the centre of this case says she was approached by church members in Paris more than 10 years ago, and offered a free personality test.

BBC: Scientology on trial in France

You can sign up for a free beta test, though.

FORBES: CES update: Can Mousemail.com make the Internet a safer place for children?

Costco provides a free hearing test and product demonstration.

WSJ: Conquering Retirement: Hearing-Aid Shopping Tips