After the rainstorm, Xiao Wei found that the water he drank at home became turbid. He used a mineral water bottle to design a device as shown in figure 1 to collect purified water. If you think Xiao W

After the rainstorm, Xiao Wei found that the water he drank at home became turbid. He used a mineral water bottle to design a device as shown in figure 1 to collect purified water. If you think Xiao Wei's design is clean, The commonly used methods for purifying water are precipitation, filtration, adsorption and distillation. The quartz sand in the title plays the role of filtration. There is a big gap in the quartz sand, so the sand can't be completely filtered out. A piece of gauze on the quartz sand and a piece of gauze under it (sponge is also acceptable) can make the water filter cleaner.

On the left, the factory is discharging sewage into the river, and on the right, the child is telling his mother to save water. The earth is rich in water resources, but there are not many available fresh water resources. In order to protect the limited freshwater resources, we should save water and cherish every drop of water.

So the answer is:

Put an emery cloth above the quartz sand and an emery cloth below it (or use reasonable materials such as cotton and sponge);

(1) Save water;

(2) Take good care of water resources.