A bit of clarification might be needed here:
There are two sorts of adverts which you could be seeing. Those which are embedded in this page, for example, (and appear down the right-hand side) are meant to be there. The Answerbank accepts payments from advertisers for those ads to appear; it's what pays for this site. So the Editor isn't best pleased when the use of AdBlock Plus is suggested, as the site might lose its advertisers and the revenue they bring in. (However I'm sure that many people do still use it as it gets rid of all such ads from every site you visit, helping them to load faster).
However you might also be getting unwanted pop-up ads, which are absolutely nothing to do with the sites you're visiting. (i.e. they'll still appear even when you go to an advert-free website, such as that of the BBC). They're generated by MALWARE on your computer and AdBlock Plus WON'T get rid of them. Instead, you need to download, install and run the free version of Malwarebytes Anti-Malware:
https://www.malwarebytes.org/antimalware/
NB: When installing it, take great care to deselect the pre-ticked option to take a free trial of the Premium version. Don't be surprised if a scan takes ages; that's normal. When malware is found, use the 'quarantine' option to zap it.