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

The diagram illustrates how a basic water filter is assembled and the way it turns a dirty supply into drinkable liquid.

Overall

Linking Words

, it is clear from the data that the device consists of two containers joined by a pipe, and that purification depends on three layers of natural material, so the amount of impurities falls significantly as the contents move downwards.

According to

Linking Words

the first part of the drawing, the main barrel is built by placing gravel at the bottom, followed by a thicker layer of charcoal and,

lastly

Linking Words

, sand at the top, a section that represents the largest proportion of the fill.

Next,

Linking Words

a hose is fitted through the base, and

this

Linking Words

connects to a separate storage tank with a tap.

Furthermore

Linking Words

, a lid covers the whole unit. The second part of the picture shows that impure water is poured in from above.

Subsequently

Linking Words

, it trickles slowly into the sand, where the majority of large particles are trapped, before reaching the charcoal, which removes a

further

Linking Words

share of chemicals. After that, the gravel filters the remaining dirt, and the purified result flows along the pipe into the tank.

Consequently

Linking Words

, if any layer were missing, the quality would drop sharply.