I don’t know _____ these old clothes
Li Feng’s __________ of devotion to others will be remembered forever in China.
The two ladies are ___ the same age, but there seems to be ten years ______ them.
We can see some apples _______ that tree and a nice bird ______ that tree.
---How is your teacher today? ---________
---_______ the balls? ---They’re under the chair.