The report examines teaching methods_______in the classroom

Who can tell me_______ —Every 15 minutes.

The time Dr. Wang has devoted _____ the disabled in the past five years is now considered_____of great value.

Passengers _____ fasten their seat belts immediately after taking their seats. The belts should remain buckled during the flight whether or not the “fasten seat belt” light is on.

You look so happy!— That’s because an old friend of iscoming.