单项选择题
| Every second, 56 hectare of the
world’s rainforest is destroyed. That’s one to two football fields. This 57 rate of destruction has serious consequences 58 the environment. Scientists estimate, for example, that 137 59 of plant, insect or animal become 60 every day due to logging. In British Columbia, 61 ,since 1990,thirteen rainforest valleys have been clear cut,142 species of salmon have already become extinct, and the 62 of grizzly bears, wolves and many other creatures are threatened. Logging, 63 ,provides jobs , profits, taxes for the government and cheap products of all kinds for consumers, so the government is 64 to restrict or control it. Much of Canada’s forestry production 65 making pulp and paper. According to the Canadian Pulp and Paper Association, Canada 66 34%of the world’s wood pulp and 49% of its newsprint paper. If these paper products could be produced in some other way, Canadian forests could be 67 . Recently, a possible 68 way of producing paper has been suggested by agriculturalists and environmentalists: a plant called hemp. Hemp has been cultivated by many cultures for thousands of years. It produces fibre which can be 69 paper, fuel, oils, textiles, food, and rope. For many centuries, it was essential to the economies of many countries 70 it was used to make the ropes and cables used on sailing ships; colonial expansion and the establishment of a world-wide trading 71 would not have been possible 72 hemp. Nowadays, ships’ cables are usually made from wire or synthetic fibres, but scientists are now suggesting that the cultivation of hemp should be 73 for the production of paper and pulp. According to its proponents, four-times as 74 paper can be produced from land using hemp rather than trees, and many environmentalists believe that the 75 scale cultivation of hemp could reduce the pressure on Canada’s forests. |