How the big forest fire has          remains to be a mystery.

After a day’s work, she felt exhausted. She____ herself on the bed, unwilling to do housework. 

Parents are advised to take pressure ____ a child and give him some encouragement before an exam.

"I ___ asleep all afternoon, so I didn’t hear the phone,"he _____ to me.

In __________ it’s not shocking to see students in __________ on college campus.