呼吸困难根据临床特点分为吸气性呼吸困难、呼气性呼吸困难和______。
参考答案：混合性呼吸困难
根据句意和首字母写单词。
1. New Year is a traditional f_________ for Chinese people.
2. There are t_________ months in a year.
3. She often borrows books from the school l_________.
4. It is very h_________ in summer.
5. He was late for class because he m_________ the first bus.
近些年来，有些农村地区存在大量焚烧农作物秸秆现象，这种做法不仅污染环境，还常引发火灾，是应当禁止的行为．根据所学知识可知，农作物秸秆燃烧时，其主要生成物除了粉尘、一氧化碳外、还有______．因此大量焚烧秸秆增加了温室气体的排放，危害环境．另外，秸秆燃烧时其化学能转化为______能，白白损失掉了．
