a) Since she had met him only one time before, she was apprehensive about going to the beach with him.
b) He was apprehensive before joining the team, but it turned out to be a good experience.
c) She was apprehensive before taking the test because she knew that she was going to get an "A" on it.
d) He was apprehensive before meeting his future mother-in-law for the first time.
APPREHENSIVE is "a feeling of discomfort or fear about something that is going to happen."
