题目内容
It will become easy to cure some serious diseases because__________.
查看答案
搜索结果不匹配？点我反馈
更多问题
根据死因监测系统的报告数据，甲地1991年肺癌死亡率是14/10万，1998年肺癌死亡率是18/10万，则1998年与1991年相比肺癌死亡率增长了 ()
根据下面材料，回答题。
It is predicted that there will be 5 scientific breakthroughs in the 21st century. We"ll know where we came from. Why does the universe exist？ To put it another way， why is there something instead of nothing？ Since the 1920s， scientists have known the universe is expanding， which means it must have started at a definite time in the past. They even have developed theories that give a detailed picture of the evolution of the universe from the time it was a fraction of a second old to the present. Over the next couple of decades， these theories will be refined by data from extraordinary powerful new telescope. We will have a better understanding of how matter behaves at the unfathomably high temperatures and pressures of the early universe.
We"ll crack the genetic code and conquer cancer. In 19th century operas， when the heroine coughs in the first act， the audience knows she will die of tuberculosis in Act 3. But thanks to 20th century antibiotics， the once dreaded， once incurable disease now can mean nothing more serious than taking some pills. As scientists learn more about the genetic code and the way cells work at the molecular level， many serious diseases——cancer， for one- will become less threatening. Using manufactured "therapeutic" viruses， doctors will be able to replace cancer causing damaged DNA
with healthy genes， probably administered by a pill or injection.
We"ll live longer （120 years？） If the normal aging process is basically a furious， invisible contest in our cells- a contest between damage to our DNA and our cells ability to repair that damage- then 21st century strides in genetic medicine may let us control and even reverse the process. But before we push scientists to do more， consider: Do we really want to live in a world where no one grows old and few children are born because the planet can hold only so many people？
Where would new ideas come from？ What would we do with all that extra time？
We"ll "manage" Earth. In the next millennium， well stop talking about the weather but will do something about it. Well gradually learn how to predict the effects of human activity on the Earth，its climate and its ecosystems. And with that knowledge will come an increasing willingness to use it to manage the workings of our planet.
We"ll have "a brain road map". This is the real "final frontier" of the 21st century: The brain is the most complex system we know. It contains about 100 billion neurons （roughly the number of stars in the Milky Way）， each connected to as many as 1，000 others. Early in the next century， we will use advanced forms of magnetic resonance imaging to produce detailed maps of the neurons in operation. We"ll be able to say with certainty which ones are working when you read a word， when you say a word， when you think about a word， and so on.
The sentence "In 19th century operas， when the heroine coughs in the first act， the audience knows she will die of tuberculosis in Act 3" means__________. 查看材料
根据下面材料，回答题。
Lead Pollution (铅污染)
Lead deposits, which accumulated in soil and snow during the 1960&39;s and 70&39;s, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation worldwide has decreased significantly.
A study published recently in the journal Nature shows that air-borne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic (北极的) snow were declining.
In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate (区分) the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States.
In a study published in the journal/Imbio (人类环境杂志), scientists found that lead levels in soil in the Northeastern United States had decreased markedly since the introduction of unleaded gasoline.
Many scientists had believed that the lead would stay in soil and snow for a longer period. The authors of the Ambio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed the lead faster than the scientists had expected.
Scientists say both studies demonstrate that certain parts of the ecosystem (生态系统).respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute.
The study published in the journal Nature indicates that__________. 查看材料
What is the author‘s attitude toward schooling？ 查看材料
微信支付 
支付宝支付