I’m wondering why Mr. Smith hasn’t _yet.

Peter _________ a baseball, but he doesn’t ________ a baseball bat.

He is the most excellent student in our class, and he always ______ himself in his studies.

Practising Chinese Kung fu can not only _____ one’sstrength, but also develop one’s character.

How is your plan getting along—I can’t ______ alone any longer. Someone must help me.