煤炭、稻谷等可燃物质长期堆积在一起可能发生自燃火灾，其点火源是()。
A．摩擦生热
B．化学自热
C．蓄热自热
D．绝热压缩
参考答案：C
三峡一期工程结束后的当年发电量为55亿千瓦时，某市10万户居民平均每户年用电量2750千瓦时，则三峡工程该年所发电能可供该市居民使用______年．
用括号内所给词的适当形式填空
1. I'm __________(save) the money for my new bike.
2. If I had a 3-day holiday, I would go __________(sail). I think it would be
very __________( fascinate).
3. Would you like __________(join) a swimming club?
4. He __________(buy) an apartment to live in.
5. We __________(especial) love hiking and swimming.
