题目

我们应该了解一些有关水的知识。请你回答： (1)天然水中含有许多杂质，可利用吸附、沉淀、过滤和蒸馏等方法净化，其中净化程度最高的方法是____________。 (2)自来水厂生产水时，使用的净水方法有________。 A．沉淀     B．过滤 C．煮沸     D．蒸馏 E．吸附 (3)取水后加入絮凝剂(明矾)的作用是__________________________。 (4)用活性炭净化水，是利用它的__________，除去水中的杂质和异味。 (5)硬水给生活和生产带来很多麻烦，生活中可用______________来区分短文理解：下面你将听到一篇短文，请根据听到的短文的内容选出正确的选项完成第1-5小题，短文读两遍。 1. How old is Li Fang? [     ]A. She is thirteen years old.B. She is twelve years old. C. She is eleven years old. 2. Where is Li Fang's home town? [     ]A. It is near the sea. B. It is in Zhejiang Province. C. It is not far away from Beijing 3. What do we know about the buildings in the town? [     ]A. There aren't many buildings in the town. B. Most of them are not very tall.C. Most of them are tall buildings 4. How often does Li Fang go to the cinema? [     ]A. She goes there once a week.B. She goes there once a month C. She goes there twice a week. 5. Why is there not much pollution in the town. [     ]A. Because there are many birds in the town. B. Because there are many trees in the town. C. Because there aren't many cars in the town.