A The Class 1, Grade 8 students are learning about pollution. Listen to the introduction to four types of pollution and fill in the blanks.

Today we're going to talk about the four main types of pollution.

Soil is polluted by chemical waste and other rubbish from humans. Cutting down too many trees can also lead to soil pollution.

Then, there is noise pollution. This is usually caused by cars, trucks and buses on the road. Noise from building work also creates noise pollution.

Air pollution is another big problem. Most air pollution is caused by the burning of unclean fuels. Smoke from factories pollutes the air as well.

Finally, water in rivers,lakes and seas is polluted because of many human activities. For example, people pour chemicals into rivers and lakes. Wastewater also adds to water pollution.