> **Possible Duplicate:**  
> [Using the gerund two times in a row](http://english.stackexchange.com/questions/14327/using-the-gerund-two-times-in-a-row)  

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Here is the sentence:

> Just as on smoking, voices now come from many quarters (**insisting**
> or **insist**) that the science about global warming is incomplete,
> that it's Ok to keep pouring fumes into the air until we know for
> sure.

Which is correct in the parentheses above, **insisting** or **insist**? Which role does it play here, attribute or some thing else? And could you help me analyze the grammar?