用所给动词的适当形式填空。
l. When I was crossing the street yesterday, I saw an old man _____ (lie) on the street.
2. He is doing his best _____ ( learn) how to swim.
3. All the Chinese people were _____(exciet) when they knew Xu Haifeng won a gold medal in shooting.
4. The teacher told us such _____ (amaze) news that some of us didn't believe it.
5. My younger brother is able_____ ( do) the work all by himself.
