Hot-hotter- the hottest и тд. Нужно так написать

1.a garbage is not only ugly, bute dangerous because it causes an air pollution.

2. cars are an important part of a life for most people. but cars also cause a pollution and release fume.

3. in canada people don't realise that they throw out 10,000 tons of a waste.

4. over 14 billion pounds of a waste per year is throw out to sea and it kills millions of sea animals.

5. if we want to breathe  a healthy air we have to think about what we do.

6. because of our lack of a knowledge there is now a huge hole over an antractic.

7.a water is a vital element of a life.

1)linda will arange the students exchange, will not she ?

2)your parents were not at the cinema yesterday, were they?

3)denis can play the guitar, can' t he?

4)we are not going to write her a letter, are we?

5)you have a lot of friends, have not you?

6)some members of his football team gave an interview to youth magazine, did they?

wild elephants have strong family ties. the females and young are social, living in groups under the leadership of an older female or matriarch. adult males are solitary, although they stay in contact with the females over great distances, using sounds well below the range of human hearing. family groups communicate with each other using these low-frequency vibrations. it is an eerie sight to see several groups converging on a waterhole from miles apart, apparently by some prearranged signal, when human observers have heard nothing.  the natural lifespan of an elephant, about 70 years, is comparable to a human's. elephants reach breeding age at about 15 years of age. females generally give birth to one 200-pound baby after a 22-month pregnancy.