"a landlord agreed to let a tenant do all necessary repairs in exchange for a lower rent rental rate for an upstairs apartment. after the tenant completed the repairs, the tenant notified the landlord of a defect in the stairs leading to the apartment that remained unrepaired. after some discussion, the landlord finally tried to repair the stairs but did an inadequate job, and the tenant fell through them and was injured."

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.