You are late . What’s the matter ? —I helped an old man _______ lost his way home .

We know Jackie Chan _____ movies are very popular with the young. [ ]

I think this bike belongs our teacher. She likes red bikes.

Newton was sitting under an apple tree ______ an apple fell onto his head.

What do you think of the four classics (名著)of China?－I hear that they are wonderful, but I’ve read _______ of them.