As act 4 opens what is to take place at daybreak

walter refusing lindner's offer.

not sure maybe the subject closer to it or subject-verb agreement

  this riddles' answer is library.

  the "leaves" are a reference to the books' pages that the library contains; the branches are a network of libraries that connect multiple libraries' collections, resources, and items in a system of a common database, integrating them; the branches' organization are a useful management tool for coordinating the multiple collections many libraries have.

black citizens were denied access to the same public facilities as whitesun.

marriages between white and nonwhite citizens were forbidden.

nonwhite citizens were required to carry identification papers with them at all times.