You can also refer to the number of empty locations as the number of free page frames.

也可以将空闲位置的数目称为空闲分页框架的数目。

youdao

We created a free page in a few minutes, but it's ham-fisted compared to what other users have devised with the same tools.

我们在几分钟之内就创建好了一个免费页面（link），但是我的这个页面跟其他用户使用同一工具创建的页面（link）相比要差不少。

youdao

When the number of free page frames gets to a low value, the AIX kernel must empty out some locations in real memory for reuse of new pages.

当空闲分页框架的数目达到某个较低的值时，AIX内核就必须清空实际内存中的某些位置，以便重用新的分页。

youdao

Here is how it works: Users can set up their own Twitter page by joining the free service on Twitter.com.

VOA: special.2009.02.06

For a business, that is one important dividend your Free page could garner.

FORBES: As a Business Owner, Which Social Media Platform Should You Use?

The Post seems likely to emulate the metered model adopted last year by The New York Times, which permits users a limited number of free page views per month before requiring a subscription.

FORBES: Connect

Beyond the couple of free home page articles and the 100 free top articles, non-subscribers will only see the first 100 words or so of each article.

WSJ: Encyclopaedia Britannica Now Fits Into an App