<span>Global warming is one of the most important problems is being discussed all over the world. Global warming is the result of constant pollution of the environment. This leads to the fact that the average temperature on the planet, including the poles, invariably grows and the glaciers begin to melt. This phenomenon is very dangerous for people, because the entire climate picture of the planet is changing. Many islands can disappear under water, and some parts of the continents will become unsuitable for human life. This problem should touch every person. The pollution of the environment depends on us. Factories and all industries are obliged to use all modern methods to clean up production waste not to let them enter the oceans and atmosphere of the Earth. </span>
2. Has it rained today? – Yes, it has. No, it has not.
3. Have you done this exercise
before? – Yes, I have. No, I have not.
4. Has life got better for people?
– Yes, it has. No, it has not.
5. Have the world’s temperatures risen? – Yes, it has. No, it has not.
6. Has the price of petrol gone
up? – Yes, it has. No, it has not.
7. Have you seen the play at the theatre? – Yes, I have. No, I have not.
8. Has the football season begun? – Yes, it has. No, it has not.
<span><span>1. By the time I got to the station the train had left.
</span>2. Patrick's mother was very angry when he came home late because she had been worrying about him all evening.<span>
3. The children started a fire. They had been playing with matches.</span><span>
4. Brenda had disappeared before I had time to talk to her.</span><span>
5. Bruce went to hospital because he had cut his hand while he was trying to </span>mend a broken window.<span>
6. It had been more than a month before I realized what had happened.</span><span>
7. When Jack had not arrived by 6 p.m. I knew he had missed the bus.</span><span>
8. When I met him he had been working as a plumber for a year or so.</span><span>
9. We had scarcely started eating when there was another scream.</span><span>
10. We had looked through the agreement before we signed it.</span>
</span>
1. hairdresser
2. teacher
3. footballer
4. pilot
5. photographer
6. mechanic
7. carer
8. secretary
9. vet