1、David was not on the bus _______ arrived just.I'll have to wait another ten minutes.

1、David was not on the bus _______ arrived just.I'll have to wait another ten minutes.
A.he B.that C.who D.it
2、We'll fly to New York on Monday morning.Then ,we will stay in New York ______ Wednesday afternoon.
A.until B.after C.on D.in
特别是第一道题.
能说一下定语从句的用法吗？我还没学到这里。