Helping things to grow

Growing plants ?.. sunlight, carbon dioxide gas from the air, and water from the soil. ?.. they get anything else? Certainly. Plants ?.. get other things from the soil, especially potassium, nitrogen and phosphorus, if they are to thrive.

Soil contains some of these materials, but farmers ?.. get good yields of crops if they do not put extra amounts on the fields when they sow the seeds in spring.

Wheat, barley and oats take a lot of nitrogen from the soil, and so the farmer ?.. use a lot of nitrogen fertilizers (ammonium, sulphate or nitrate) when he plants these crops. Another way of putting nitrogen into soil is by growing beans, peas and clover. There are bacteria living in the roots of these plants that take nitrogen gas out of the air and change it into nitrogen fertilizer in the soil. After growing clover - for the farm animals - the farmer ?.. grow a good crop of wheat the next year in the same fields, and he ?.. not put any nitrogen fertilizer in the soil.

There are tiny plants (plankton) growing on the surface of the sea. What ?.. they got for their growth? They ?.. the same materials for growth as the plants we ?.. see on land. There is plenty of potassium in sea water, but not much nitrogen or phosphate, so if we add fertilizers there will be a bigger growth of these tiny plants.

But why ?.. we care about plants growing in the sea? Small sea plants in turn are eaten by fish. If there are more plants (plankton) there will in time be more and bigger fish for us to catch and eat. The scientists ?.. to increase the fish in the open sea.

Complete the sentences with these verbs in correct forms.

1) Muscle cells ?.. live for a long time, but nerve cells cannot.

2) Leukocytes?.., like Amoeba, to ingest solid particles.

3) To carry out its functions the blood ?.. be made to circulate throughout the body.

4) All forms of animals ?.. digest food, because most forms of food are insoluble and therefore ?.. pass through walls of the digestive tract into the blood stream.

5) It we begin working out routes of migration of birds in the British Isles, we shall ?.. include lakes and river valleys in all directions.

6) The necessary supply of oxygen for breathing ?..be got from the air, or, in the case of aquatic animals, from the air dissolved in the surrounding water.

Offers and suggestions

Write your own sentences according to the following patterns:

Would you like ?..? (offer)
Let?s ??... (suggestion)
Shall we ??..? (suggestion)
Can I help you ???.? (offer informal)
If you don?t mind???.. (offer informal)
Why don?t we????..?(suggestion)
How about ????.? (suggestion)

Advice and Criticism

Complete the sentences with these verbs.

1) You ?.. (cut) down on the amount of chocolate you eat.

2) He ?.. (make) more of an effort with his work.

3) Do you think I ?.. (be) in a hurry with this report?

4) Anna ?.. (take) part in that conference last month.

5) Mike ?.. (include) more articles in the bibliography.

6) Conservationists?.. (take) more decisive measures to prevent the oil spill.

Permission

Date: 2016-06-12; view: 282