But generally, Any of the #Googleads pro you come across would be using a single adgroup with all the above keywords dumped into the adgroup.
It is a wrong way to do #PPC
Instead, Break your #ppc structure into many campaigns or adgroups based on your convenience as below
One Campaign for QA Training
One Campaign for QA Certification
One Campaign for Quality Assurance Training
One campaign for Quality Assurance Certiication
Now in QA Training Campaign –> Add Certification, Quality, and Assurance as Negative keywords (Campaign level). By doing so, you can be sure that you create a perfect ad with QA training in the ad text and also create a perfect landing page that talks only about QA Training. This will improve your CTR and Adrank also.
The same can be followed for remaining campaigns,
Quality Assurance campaign will have, QA , Training as negative keyword.
All the best.