difficult questions the teacher is asking! Only a few students can answer them!
—Whose volleyball is it? —It ________ Carla’s. She doesn’t like volleyball at all.
—_______ do you improve your English? —I improve it _______ reading aloud.
After a heavy rain , There is ___________ water on the playground .
If he ________harder , he will catch up with us soon .
Beijing is one of the _________________ in the world today .