=>

XIII/

1. Light pollution makes us unable to see the stars in the sky.

2. Glass panels, windows, lawns and roofs make light pollution worse because they reflect artificial and sun light.

3. All sound are not noise because noise is any sound that is unwanted and goes beyond its certain limit, for example, above 80 decibels.

4. More and more noise is created by modern civilization, so it has now become a major environmental pollutant, especially in urban areas. (so)

5. Contamination in the air causes acid rain which damages soil, vegetation and aquatic life of the region.

6. People suffer from stress and anxiety because of noise pollution.

XIV/

1. If my home installed a solar water, we would save a lot of energy. 

2. If all households in Vietnam turn off lights during the Earth Hour, we would enough electricity to develop our rural areas.

3. If students in our school didn't throw litter on the school ground, our campus would look greener and fresher.

4. If people used glass bottles, they would use them again and again.

5. If we installed a wind turbine, our school would become more eco-friendly.

6. If people used organic fertilizers, they would prevent land pollution.

7. If people rode bikes, they would keep the air less polluted.

XIII. Combine each pair of sentences, using the words/ phrases in brackets. You can make some changes.

1. We are unable to see the stars in the sky.Light pollution occurs.(makes)

=>Light pollution makes us unable to see the stars in the sky.

2. Glass panels, windows, lawns and roofs make light pollution worse. They reflect artificial and sun light. (because)

=>Glass panels, windows, lawns and roofs make light pollution worse because they reflect artificial and sun light.

3. All sound are not noise. Noise is any sound that is unwanted and goes beyond its certain limit, for example, above 80 decibels. (because)

=>All sound are not noise because noise is any sound that is unwanted and goes beyond its certain limit, for example, above 80 decibels.

4. More and more noise is created by modern civilization. It has now become a major environmental pollutant, especially in urban areas. (so)

=>More and more noise is created by modern civilization; therefor, it has now become a major environmental pollutant, especially in urban areas.

5. Contamination in the air happens. There is acid rain which damages soil, vegetation and aquatic life of the region. (causes)

=>Contamination in the air cause acid rain which damages soil, vegetation and aquatic life of the region.

6. Noise pollution is one of the major causes of stress and anxiety. People suffer from stress and anxiety. (because of)

=>People suffer from stress and anxiety because of noise pollution