3 Read the text again. Are the sentences true or false? 1 George and David were alone at home. 2 George and David's parents were on a day trip with their friends. 3 Both boys were bored at home. 4 George and David's friends, Sally and Emily, were at the cinema. 5 David believed that he caused the dent. 6 The mechanic repaired the dent before their parents arrived home. 7 The dent was there before George and David used the car.
2.Have you got a pet? - Yes, I have.- No, I haven't.
3.Do your parents work in the morning? - Yes, they do.- No, they don't.
4.Are your friends English? - Yes, they are. - No, they aren't.
5.Has your teacher got long hair? - Yes, he has.- No, he hasn't.
6.Does your best friend like football? - Yes, he does.- No, he doesn't.
7.Does your English teacher give you a lot of homework? - Yes, she does- No, she doesn't.
8.Is there a zoo in your town? - Yes, there is.- No, there isn't.
9.Do your friends live near you? - Yes, they do.- No, they don't.
More and more often people are told not to be in direct sunlight, because ultraviolet radiation from the sun can cause skin cancer. Normally the ozone layer in the atmosphere protects us from such radiation, but if there are holes in the ozone layer ultra¬violet radiation can get to the earth. Many scientists think that these holes are the result of air pollution.
Nuclear power stations can go wrong and cause nuclear pollution. This happened in Windscale in Britain, in Three Mile Island in the USA and Chernobyl in the former Soviet Union. Nuclear pollution cannot be seen but its effects can be terrible.
To make air clean again we need good filters at nuclear power stations, at factories and plants and also in cars and buses.
Both clean air and clean water are necessary for our health. If people want to survive they must solve these problems quickly. Man is beginning to understand that his environment is not just his own town or country, but the whole earth. That's why people all over the world think and speak so much about ecology.