Both nadir and zenith of the entertainment world (you decide which is which) will appear here in the next several days as the final pref exam diversion available to students. The Artists Series will present Romeo and Juliet by the National Shakespeare Company tonight at 8:30 in University Hall. The Circle K Club will sponsor Jackie Wilson (right) and Neil Diamond in concert in University Hall tomorrow night at 8. The Tuesday Evening Concert Series will present the Koeckert Quartet (string), originally scheduled for February 20, Tuesday at 8:15 p.m. In Cabell Hall.