French language Q&A Forum

I am puzzled that the correct way of expressing leaving work uses laisser rather than quitter, both of which require direct objects. Where travail is the direct object, why is "J'ai quitté le travail" marked incorrect in the quiz and "J'ai laissé le travail" marked correct? I do not dispute that "J'ai laissé le travail" is correct, but the lesson on partir, quitter, laisser, etc. is unclear. This is especially true if "travail" is considered a place and quitter is used for leaving places, which to me at least seems plausible. I have not yet taken this up with my French coterie.

when the "re" comes before the verbs(for example redonner) does it give the verbs the meaning of again and back everytime? or does it change according to the verbs?
for example:
Je lui ai redonné son style: I gave back him his pen(?)
Je lui ai redonné mon stylo: I gave him my pen again(?)

thanks for comments

I enjoy these weekly writing challenges and learn a lot through them.  Still, I become a little frustrated when it becomes evident that I have chosen different  French translations for the suggested English words presented.  My choices may be fine synonyms at best, but the  concern is that they aren't really the best words for those contexts.  I recognize the value of looking things up ourselves,
but would it be possible to provide the exact French vocabulary we are to learn for these exercises instead of the English? 

How do you decide when to use "du monde entier" vs. "mondiaux" vs. "a travers le monde" ?