The diagram below shows how a simple water filter is constructed to produce clean drinking water. Summarize the information by selecting and reporting the main features, and make a comparison where relevant.

The given diagram illustrates the working process of a filtration system to make clean drinking

water

.

Overall

,

this

is a man-made cyclical process which includes a total of 5 stages. It starts with pouring raw

water

into the first

barrel

and ends with purified

water

coming out of the tap. Looking at the diagram from a more detailed perspective, it can be clearly seen that

water

must first be poured into a

water

container before being cleaned. The purifying system contains three main materials namely sand, charcoal and gravel so that it can remove even the most microscopic contamination from the

water

without boiling it and killing good bacteria. After that, a hose connects

this

barrel

to another one and gravity assists in

this

process.

This

is achieved by placing the filtering

barrel

in a higher position than the containing one.

Then

, the freshly purified

water

will flow naturally into the drinking storage tank sitting right below.

Last

but not least, opening the tap attached at the bottom of

this

barrel

can quench the thirst of many.