Ecology. Problems.

The .......             [poisononing, poisonous, poison, poisoned] of the world's land, air, and water is the fastest-spreading disease of civilisation. It probably .....            [production, produces, produce, produced] fewer headlines than wars, earthquakes and floods, but it is potentially one of history's greatest......            [dangerous, dangers, endangered, dangered] to human life on earth. If present trends continue for the next several decades, our planet will become uninhabitable.

Overpopulation, pollution and energy consumption have .....          [create, created, creation, creates] such planet-wide problems as massive ....               [deforestation, cut down, forest, food], ozone depletion, acid rains and the global warming that is believed to be caused by the greenhouse effect.

The seas are in danger. They are filled with poison: industrial and nuclear .....         [waste, garbage, litter, rubbish], chemical fertilisers and pesticides. The Mediterranean is already nearly dead; the North Sea is following. The Aral Sea is on the brink of ....               [deforestation, destruction, extinction, endangered]. If nothing ...      [are, is, were, was]done about it, one day nothing will be able to live in the seas.

Every ten minutes one kind of animal, plant or insect dies out for ever. If nothing is done about it, one million species that are alive today will have become extinct twenty years from now.

Air .....               [deforestation, pollution, ozone layer, garbage] is a very serious problem. In Cairo just breathing the air is life threatening- equivalent to smoking two packs of cigarettes a day. The same holds true for Mexico City and 600 cities of the former Soviet Union.

Industrial enterprises emit tons of harmful substunces. These emissions have disastrous .....              [reason, cause, consequences, effect]for our planet. They are the main ....        [reason, cause, result, task]for the greenhouse effect and acid rains. And even greater environmental .......        [cause, reason, threat, effect]are nuclear power stations. We all know how tragic the consequences of the Chernobyl ......          [disaster, result, cause, reason].

People are beginning to realise that environmental problems are not somebody else's. They join and support various international organosation and green parties. If governments wake up to what is happening- perhaps we .......               [are able, will be able, would be able, be able] to avoid the disaster that threatens the natural world and all of us with it.

Read the sentence and fill in the correct form of the verb ( 1 conditional, 2 conditional)

1. If we stop the pollution our planet ...... ( survive)

If they ..... (cut down) the forests we can't breathe the fresh air.