Fill in: prevent, contains, ailments, kills,
helps.
You can put it on your salad and
use it to make pickles, but vinegar
has got many other uses, too! The type
that is made from apples 1) lots of
vitamins, but it's also a great natural remedy.
Gargling with water and vinegar before you
brush your teeth 2) bacteria and
makes your teeth whiter. Soaking your feet in
water with a little vinegar makes your skin softer,
relaxes your muscles and 3)
you sleep. You can also mix vinegar with
warm water and honey - it's great for
such as coughs and
colds. Research suggests that a drink
made with vinegar can also help weight
loss and 5)
problems
with blood sugar.​

1. The letters have not been sent yet.
2. Have you sent the letters already?
3. I sent them tomorrow.
4. Please, make sure that the letters have been sent by tomorrow evening.
5. The letters were not sent yesterday because we forgot to buy stamps.
6. Finally the letters were sent.
1. The article was being when I came in the classroom.
2. The article has not been translated yet.
3. It was not translated yesterday, so it needs to be translated today.
4. If we do not finish it today, we shall  translate it tomorrow.
5. The article will have been translated by the end of the week.
6. If I am not mistaken, the article was translated some time ago.
7. I am afraid this article will never be translated.

1) People so often speak about ecology these day because this science is very important.

2)  Ecology is an important science because it deals with world-wide problems for humanity and it is a science about our environment.

3) People first started speaking about ecology in the 20th century.

4) It uses the information of zoology, biology, chemistry, geography and some other sciences.

5) There are a lot of problems and the most important are different kinds of pollution ( air, water, land ), global warming, destruction of ozon layer and many other problems.

6) It has a great impact on every living thing, for example when we pollute water in rivers and lakes fish die and many animals have lack of food if they  use fish as their food.

7) Human ecology studies the problems with nature which are connected with people.

8) My natural evironment isn't healthy. I live in a big city and it is very dirty because of cars and buses fumes. The air is bad and the soil is also polluted.