There is a kind of false precision being hawked by people.

划线部分，是现在分词的被动式作定语修饰 precision。

There is a kind of false precision being hawked by people.

【直译】有一种被人们兜售的测试的不准确性。

【意译】人们兜售的测试有一定的不准确性。

to be done, being done, done, having been done 作定语的区别

以上四种形式都可表示被动，同时都可作定语，但它们在作定语时，是有明显区别的。to be done 表示“即将被做”，being done 表示“正在被做”，done 表示“完成 + 被动”，having been done 一般是非限制性定语，因为过去分词 done 已经表示“完成的概念”。

The meeting being held now is of great importance. 现在正在召开的会议很重要。

The meeting held yesterday is of great importance. 昨天召开的会议很重要。

The meeting to be held tomorrow is of great importance. 明天要召开的会议很重要。

The meeting, having been held, is of great importance. 会议已召开，会议很重要。