Parents should pay attention to areas _______ their child is having difficulty and spend extra time to help him or her master those skills.
A. as B. where C. why D. when
We apologize for any inconvenience you _______ have been caused by the delay of the flight.
A. may B. would C. must D. need
The police say there is a $50,000 _______ for any information that helps them find the killer.
A. income B. fee C. bill D. reward
Most whales must come up for air after several minutes, _______ a few can stay under water for an hour or more.
A. while B. or C. for D. so
The numbers that researchers get from the experiments can be _______, just like number puzzles.
A. disappointing B. inspiring C. worrying D. confusing
_______ the house is empty, memories flood my mind of a time when it was filled with life.
A. Since B. Unless C. As if D. Even though
