Read the passage carefully.

We may take it for granted, but water is the most important resource on Earth. It covers 80% of the Earth’s surface, and it’s the only substance that can be found naturally in three forms: solid, liquid and gas. Water also makes up 66% of the human body, and without it, we can’t live for more than a week.

Although water is the most common substance on Earth, we should use it carefully because only 1% is drinkable, and 1/3 of all the people in the world can’t get enough clean water. Today, we use three times more water than in 1950, and people in rich countries use ten times more than those in poor ones. So, where does it all go? Well, a single dripping tap can waste up to 7,600 litres of water in a year, and a leaking toilet can waste about 260 litres in a day.

At home, we can help by fixing broken taps and toilets. Having showers instead of baths could save about 300 litres of water a week. We should also avoid using chemicals that pollute the water supply because we can’t increase the amount of fresh water in the world. We can only change the way we use it.