Hi Leo N
Welcome to the AdWords Community...!
Yes, you can use these words as keywords but their are certain guidelines. Please read the below:
We value honesty and fairness, so we don't allow the promotion of products or services that are designed to enable dishonest behavior.
Examples of products or services that enable dishonest behavior: Hacking software or instructions; services designed to artificially inflate ad or website traffic; fake documents; academic cheating services
If you want to promote custom written assignments or thesis services then I think it is not allowed but if it is a kind of professional assistance(even paid) then I think you can run AdWords ads for this.
@MosheTLV, need your help here...!