( ) 1. None of us knew what had happened _______ they told us about it.
A. when B. until C. after D. though
( ) 2. Mrs. Smith was worried about both of her daughters, especially the ________ one.
A. young B. younger C. youngest D. oldest
( ) 3. The dogs were made __________ as fast as they could.
A. run B. ran C. running D. to run
( ) 4. My friend Tom _______me __________ for an hour yesterday.
A. keep; wait B. keeping; waited
C. kept; waiting D. keeps; to wait
