Why did the students post their “twelve theses” in the entrance hall of the university?

to show their opposition to Nazi policies
to show their support for a Jewish teacher who was about to be fired
to demand reforms to university tuition policies
to call for the expulsion of all non-German professors

To call for the expulsion of all non-German professors.

Explanation:

"The Twelve Theses" was a text published by the German Student Union. These books called for the elimination of all "Jewish aspects" of culture from German literature. Among many other requests, it asked for a ban on publishing works by Jewish authors in Germany, and a ban on German translations of foreign books. It also called for the expulsion of non-German professors.

one of the major compromises in the constitutional convention was between the small states and big states. the small states wanted each state to have the same number of representatives in congress. the big states wanted representation based on population.