A change, modifcation or addition​

Black death spread because of what problem in medieval europe? which one is it i need the answer quick . a- overcrowded cities b-too many farm animals c-not enough qualified doctors d-all of the above

Before they can be published, scientific papers must be peer-reviewed. this means that: a) some other scientific experts read the papers and guarantee that they are true.b) some other scientific experts read the papers and provide quality control by eliminating many mistakes.c) an editor reads the papers, to make sure that all the semicolons are in the correct places.d) everyone in the world is given the opportunity to comment on the papers through a specially maintainedblog.e) government bureaucrats read the papers, to be sure that the papers do not insult the political positions ofthe current officeholders.

These two countries developed a strong trading relationship during the time of the renaissance. name them?