Where does the water in our homes come from? How do people change sea water into fresh water? How does water come into our homes? This passage will answer these questions.

In most places, people get their water from lakes and rivers. The water is usually seen all year round. In some places, people get their water from under the ground. They use wells to get the water. In some other places, windmills (风车) are used to get water from under the ground. In some country areas away from the city water supply, people collect rainwater that falls on their roofs (房顶). Pipes from the roofs lead the water into tanks (罐子). The water from rainwater tanks is usually clean enough to drink.

In some countries that are in need of water, fresh water is made from sea water in special treatment factories. This is called desalination (脱盐). In most treatment factories, salt water is heated until it turns into steam (蒸汽) and the salt is left behind. When the steam is cooled, it becomes fresh water. Only a little salt is left in the fresh water. This makes the water taste better and also stops the pure water taking salts and minerals (矿物质) out of our bodies.

Have you seen tanks or towers on the tops of buildings? These tanks or towers are used for storing clean water. Before the water is put into these tanks or towers, it goes to a water treatment factory. Some water from rivers or lakes is not clean. If we drink it directly, we may be ill. In the water treatment factory, workers make the water clean and safe for people to drink. Then pipes bring the water to our homes.

Water is very important for all living things, but sometimes there is not enough water. We should use water wisely.

1.1. How does the writer begin the passage?

A By comparing ideas.

B By giving examples.

C By asking questions.

D By explaining reasons.

解析：选C。题干问 “作者如何开篇”。原文开头连续提出三个问题（Where does...? How do...? How does...?），对应选项 C“By asking questions（通过提问）”。A（对比观点）、B（举例）、D（解释原因）均未体现，故选 C。

2.2. Where do people in most places get water from?

A Lakes and rivers.

B Lakes and underground water.

C Rivers and rainwater.

D Rainwater and underground water.

解析：选A。细节理解题。题干问 “大多数地方的人从哪里取水”。定位第二段首句 “In most places, people get their water from lakes and rivers”，直接匹配选项 A，其他选项均不符合 “most places” 的限定，故选 A。

3.3. What does the underlined word “it” in paragraph 3 refer to (指代)?

A Rainwater.

B Salt water.

C Fresh water.

D Pure water.

解析：选B。指代题。题干问第三段划线词 “it” 指代什么。定位第三段 “In most treatment factories, salt water is heated until it turns into steam”，结合语境，“被加热并变成蒸汽” 的是前文提到的 “salt water（海水）”，故选 B。

4.4.What are tanks or towers used for according to the passage?

A Storing salt.

B Storing pipes.

C Storing minerals.

D Storing clean water.

解析：选D。细节理解题。题干问 “储水罐或水塔的用途”。定位第四段第二句 “These tanks or towers are used for storing clean water”，直接对应选项 D，其他选项（储存盐、管道、矿物质）均与原文不符，故选 D。