The world’s oceans are so vast that they can cope with the present levels of (1) _______. However, little is known about the long-term effects of such slow poisoning. The most serious (2) _______ of modern times is that man is destroying the earth’s natural (3) _______ and transforming huge areas into wasteland. As a result, it is becoming extremely difficult to grow (4) _______ to feed the world’s rapidly increasing population. A way of protecting all the (5) _______ on the earth also be found as many species are in danger of disappearing from the surface of the earth.