Akeyword search of a library database will typically turn up
a. publication information.
b. who used the source last.
c. author contact information.
d. a detailed summary of the contents of relevant materials.

1. in which sentence is the underlined portion a predicate nominative? for astronauts, going into space to repair orbiting equipment becomes a challenge. for astronauts, going into space to repair orbiting equipment becomes tricky. for astronauts, going into space to repair orbiting equipment becomes challenging. for astronauts, going into space to repair orbiting equipment becomes frequent.