In the past century, the steady growth of the human population and the corresponding increase in agriculture and pesticide use have caused much harm to wildlife in the United States—birds in particular. Unfortunately for birds, these trends are likely to continue, with the result that the number of birds in the United States will necessarily decline.
First, as human populations and settlements continue to expand, birds' natural habitats will continue to disappear. Forests, wetlands, and grasslands will give way to ever more homes, malls, and offices. As the traditional areas suitable for birds keep decreasing, so will the size of the bird populations that depend on those vanishing habitats.
Second, agricultural activities must increase to keep pace with the growing human population. The growth of agriculture will also result in the further destruction of bird habitats as more and more wilderness areas are converted to agricultural use. As a result, bird populations in rural areas will continue to decline.
Third, as human settlements expand and agriculture increases, the use of chemical pesticides will also increase. Pesticides are poisons designed to kill agricultural and home garden pests, such as insects, but inevitably, pesticides get into the water and into the food chain for birds where they can harm birds. Birds that eat the poisoned insects or drink contaminated water can die as a result, and even if pesticides do not kill birds outright, they can prevent them from reproducing successfully. So pesticides have significantly contributed to declines in bird population, and because there will continue to be a need to control agricultural pests in the future, this decline will continue.
The passage clams that there will be fewer and fewer birds, but the arguments used to support this claim are unconvincing.
First, it’s true that urban growth has been bad for some types of birds, but urban development actually provides better and larger habitats for other types, so much so that city and suburban dwellers often complain about increased birds populations—seagulls at landfills, pigeons on the streets and so on. Even birds like hawks and falcons can now be found in cities, where they prey on the increasing populations of pigeons and rodents. So it’s not going to be a story of uniform decline of bird populations in the future. Some populations may shrink, but others will grow.
As for agriculture, it’s true that it too will increase in the future, but not in the way assumed by the reading passage. The truth is, in the United States, less and less land is being used for agriculture every year. Increasing in agricultural production have resulted from and will continue to result from the introduction of new, more productive varieties of crops. These new crops produce more food per unit of land, and as a result, there’s no need to destroy wilderness areas.
And third, while it’s certainly true that traditional pesticides have been destructive to birds, it’s incorrect to project this history into the future. Now that people are aware of the possible consequences of traditional pesticides, two changes have occurred. First, new and much less toxic pesticides have been developed, and that’s important. Second, and perhaps more importantly there is a growing trend to develop more pest resistant crops, crops that are genetically designed to be unattractive to pests. Pest resistant crops greatly reduce the need for chemical pesticides. And best of all, pest resistant crops don’t harm birds at all.
Main points: Birds number will decline in result of human growth.
Sub point 1: Birds’ habits disappear since human expand.
Sub point 2: Birds’ habitats decrease since further agricultural activities.
Sub point 3: Use of chemical pesticides will increase and kill agricultural then kill birds.
Sub Point 1: Not a uniform decline for all birds. (Bad for some, Good for some, Seagulls, Pigeons, Hawks.)
Sub Point 2: Less land is used for agriculture. (Productive Crops.)
Sub Point 3: New pesticides don't harm birds. (Less toxic, Pest resistant crops.)
The reading passage claims that the number of birds in the US will definitely decline. Yet the professor argues that bird populations will not shrink due to increases in human population, agriculture, and pesticide use as is suggested by the reading passage’s author.
First, the professor points out that urban growth, while harmful to some types of birds, can provide habitats for many other types. As a matter of fact, urban and suburban dwellers complain frequently about having too many birds. This, however, contradicts the statement in the reading passage that urban development causes birds to disappear.
Second, the professor explains that agricultural development won’t affect bird population as the reading illustrates. Newly-introduced and highly productive crops continuously contribute to production enhancement and more efficient land use, making it unnecessary for humans to destroy more wilderness areas.
Third, while convinced of the harmful nature of pesticide use to birds, the professor does not think it will be a problem in the future, in that people are increasingly aware of this problem and are developing less toxic pesticides and pest-resistant crops as solutions.
1. ……(某观点B。).This, however, contradicts the statement…(某观点A)….
2. Shrink： 收缩，缩水
There has been some shrink in our export trade.