Part 1. Rainforests/ Part 2. The World of Plants/ Part 3. Interesting Facts about Plants

Exercise 1. Change the tense of the sentence according to a time marker:

1. A sheet of cells on the top of a leaf has been absorbing sunlight all day long. V1=absorb(reg.) (every time the sun shines) – A sheet of cells on the top of a leaf absorbs sunlight every time the sun shines.

2. All trees are producing flowers at the moment. V1=produce(reg.) (next spring from March to May)

3. Wind or insects usually carry pollen from stamen to pistil. V1=carry(reg.) (two hours ago)

4. Thanks to its fireproof bark sequoias have already survived in many forest fires. V1=survive(reg.) (in the future)

5. Every spring tender light-green needles appear on the tree. V1=appear(reg.) (for many years)

6. When we returned home from our holiday the needles of the larch were turning yellow and leaving the tree. V1=turn(reg.) (by September)

7. In many European countries the buildings of larch have been standing for more than 500 years already. V1=stand(irreg.) (in 10 years for more than 500 years)

8. Next year this monkey puzzle tree will have been growing for 2000 years. V1=grow(irreg.) (When they cut this … they found that it)

9. The eucalyptus blossoming trees attracted parrots and other birds last spring. V1=attract(reg.) (when we stayed in Australia last year)

10. The fruits are ripening gradually in the sun these days. V1=ripen(reg.) (before the winter came)

Study the information in the table below:

Passive Voice Tenses

Active Voice (активный залог) – имеет место тогда, когда подлежащее является действующим лицом в предложении	Passive Voice (пассивный залог) – имеет место тогда, когда подлежащее испытывает воздействие со стороны
Present Simple Active □ V1/Vs ■. The rainforests cover six percent of the earth’s surface. V1=cover(reg.)	Present Simple Passive □ am/is/are Ved/V3 ■. Six percent of the earth’s surface is covered by the rainforest.
Past Simple Active □ Ved/V2 ■. People chopped down the trees because they wanted to grow rice. V1=chop(reg.)	Past Simple Passive □ was/were Ved/V3 ■. The trees were chopped down because people wanted to grow rice.
Future Simple Active □ shall/will V1 ■. People will grow rice on this field next year. V1=grow(irreg.)	Future Simple Passive □ shall/will be Ved/V3 ■. Rice will be grown on this field next year.
Present Continuous Active □ am/is/are Ving ■. Icy winds are intensifying the cold these days. V1=intensify(reg.)	Present Continuous Passive □ am/is/are being Ved/V3 ■. Cold is being intensified by icy winds these days.
Past Continuous Active □ was/were Ving ■. Large numbers of immigrants were settling in America through the years. V1=settle(reg.)	Past Continuous Passive □ was/were being Ved/V3 ■. America was being settled through the years.
Present Perfect Active □ have/has Ved/V3 ■. They have just cut the tree. V1=cut(irreg.)	Present Perfect Passive □ have/has been Ved/V3 ■. The tree has just been cut.
Past Perfect Active □ had Ved/V3 ■. He remembered how tornado had lifted frogs and fish from ponds. V1=lift(reg.)	Past Perfect Passive □ had been Ved/V3 ■. He remembered how frogs and fish had been lifted from ponds by tornado.
Future Perfect Active □ shall/will have Ved/V3 ■. The scientific society will have built the new satellite by next year. V1=build(irreg.)	Future Perfect Passive □ shall/will have been Ved/V3 ■. The new satellite will have been built by next year.

Exercise 2. Complete the sentences using one of the following verbs in the correct form in passive voice:

cause, grow, mine, heat, cover, call, prevent, form, bring, send

1. The corn growing … by the harsh climate and frozen subsoil for many years. – The corn growing has been prevented by the harsh climate and frozen subsoil for many years.

2. The destruction … by whirling winds yesterday.

3. The moon … by the thick layer of dust.

4. Independence … to Angola in 1975 by the nationalist war.

5. Salt … around the Bahamas these days.

6. Americans … “a nation of immigrants” for many years.

7. Comet’s tail … of dust and gas.

8. A steady steam of water vapour … up into the atmosphere by lakes, streams, and oceans usually.

9. Cotton … on this field next summer.

10. The earth’s surface in this region … by the sun by June.

Exercise 3. Rewrite these sentences in passive voice:

1. Americans have recently discovered the new comet. – The new comet has recently been discovered by Americans.

2. Ocean currents affect climate in this region. –

3. Locals are catching shrimp and fish in the coastal waters these days. –

4. The earth’s gravity pulls the rain. –

5. European sailors discovered the Antarctic continent in 1700s. –

6. The island’s inhabitants are selling lobsters overseas. –

7. Heavy masses of cold air lift warm air. –

8. Spain was ruling Argentina from 1535 to 1816. –

9. The scientists have photographed the earth’s atmosphere from space since 1961. –

10. The sun lights the moon. –

Exercise 4. Rewrite these sentences in active voice:

1. Fleshy fruits have been eaten by animals. – Animals have eaten fleshy fruits.

2. Winged fruits were spread by wind last autumn. –

3. The trees are anchored to the soil by roots. –

4. The age of this tree will be shown by the rings on the cross-section of the trunk. –

5. The alarm had been given by the loud cry in the Scots camp before they were attacked by the invaders. –

6. The leaves of this plant are being covered with the wax film. –

7. This plant will be used in medicine in the future. –

8. Many years ago the roots of this plant were added into the flour. –

9. Both the leaves and stems of sphagnum are surrounded by cells filled either with air or with water. –

10. The seeds of monkey puzzle tree have been used for food by local dwellers. –

11. Baobab flowers were pollinated by the bats last night. –

12. The putrid smell is given by the flowers of rufflesia. –

Unit 7. Wildlife