This is false
this is not true. you are allowing some sites that offer example and sample essays to advertise on adwords but not others that follow the same business model. either you need to let us all advertise or you need to remove the offenders.
Re: This is false
Just because one or two advertisers slipped through the net doesn't mean Google should let everyone through.
I'd advise that you report any advertisers violating any policy here https://support.google.com/adwords/answer/176378?hl=en