3. The doctor told my father to give up smoking

4. His business is going badly - we have to close it down

5. My aunt has got two teenage children , but they don't get on well with each other. 

I,

1B difficult

2A metropolitan

3D status

4D place

II.

1. One of the biggest environmental impacts of human activities is air pollution.

2. Smoke from aircrafts, factory chimneys, bonfires, different kinds of vehicles on streets, and many other factors damage clean air every day.

3. Industrial factories throw into the air huge amounts of pollutant gases.

4. The air in many areas is so unclean that many people have to wear masks when going out on the streets.

5. Air pollution leads to the greenhouse effect making the temperature of the earth's surface higher.

6. Global warming leads to the polar ice caps melting, the rise of worldwide sea levels, climate changes and other natural disasters.

7. Everyone living on the Earth should have the responsibility to reduce air pollution and protect clean air for our survival.

8. Worldwide governments should have control measures to reduce air pollution and protect the natural environment for the future generations.