1.The United States was also one of the very few countries that refused to sign the biodiversity treaty.
2.A desire for environmental change led to the creation of various political parties around the world whose emphasis was largely on environmental protection.
3.Destruction of the world's rain forests, global warming, and the depletion of the ozone layer are just some of the problems that will endanger mankind in the coming decades.
4.Every year, humans churn out 8 billion tons of carbon dioxide, almost all of which goes straight into the atmosphere.
5.Most scientists agree this outpouring contributes to global warming, which could eventually lead to coastal flooding, extreme weather, and widespread crop loss.
6.Finally, oil and other petroleum products that are spilled into bodies of water foul beaches and kill sea birds and mammals, such as dolphins and whales.
7.He said that this was a good suggestion, which he would look into.
8.Norway is, quite naturally, paying great attention to developments in Europe and in the Atlantic community, which are so instrumental to the maintenance of peace and security in our part of the world.
9.The cook turned pale, and asked the housemaid to shut the door, who asked Brittles, who asked the tinker, who pretended not to hear.
10.The food supply will not increase nearly enough to match the increase of population, which means that we are heading into a crisis in the matter of producing and marketing food.
11.I hope your success, which is an inspiration to me, will continue.
12.My uncle, who will be seventy tomorrow, is still a keen sportsman.
13.The way the brain works and adapts as we age is a fascinating intellectual puzzle that science is still a long way from solving.
14.Nevertheless the problem was solved successfully, which showed that the computations were accurate.
15.Never say anything behind a person's back that you wouldn't say to his face.
16.Chinese trade delegations have been sent to African countries, who will negotiate trade agreements with the respective governments.
17.The thief, who was about to escape, was caught by the policemen.
18.Liquids, which contain no free electrons, are poor conductors of heat.
19.There was something original and independent about the plan that pleased all of them.
20.The design of this mobile robot was a complex one, which took us a lot of time.