Anyone who has spent time with children knows the difference in the way boys and girls respond to __________ situations.
John _____ knowledge of radio just by staying around the radio station.
They did not find _____ to prepare for the worst conditions they might meet.
The microphone enabled them to keep in touch, in other words, it made it _____ for them to contact each other.
She is making herself ill with _____ over her son's future.