某县城一家房地产开发企业2009年度委托建筑公司承建住宅楼10栋，其中：80%的建筑

(46)The climatic phenomenon that is being blamed for floods, hurricanes and early snowstorms also deserves credit for encouraging plant growth and helping to control the pollutant linked to global warming, a new study shows.
E1 Nino—the periodic warming of eastern Pacific Ocean waters—causes a burst of plant growth throughout the world, and this removes carbon dioxide from the atmosphere, researchers have found.
(47)The new study shows that natural weather events，such as the brief warming caused by E1 Nino, have a much more dramatic effect than previously believed on how much carbon dioxide is absorbed by plants and how much of the gas is expelled by the soil.
Atmospheric carbon dioxide, or CO₂, has been increasing steadily for decades. This is thought to be caused by an expanded use of fossil fuels and by toppling of tropical forests. Scientists have linked the CO₂ rise to global warming, a phenomenon known as the greenhouse effect. (48)Alarmed, nations of the world now are drawing up new conservation policies to reduce fossil fuel burning, in hopes of reducing greenhouse gases in the atmosphere.
But David Schimel of the National Center for Atmospheric Research，a co-author of the new study, says that before determining how much to reduce fossil fuel burning we should consider the effects of natural climate variations on the ability of plants to absorb CO₂.
Schimel said satellite measurements of CO₂, plant growth and temperature show that natural warming events such as E1 Nino at first cause more CO₂ to be released into the atmosphere, probably as the result of accelerated decay of dead plant matter in the soil. But later, within two years, there is an explosion of growth in forests and grasslands, which means plants suck more carbon dioxide out of the atmosphere.
" We think that there is a delayed response in vegetation and soil to the warming effects of such phenomena as E1 Nino, and this leads to increased plant growth, " said Schimel.
(49)However, he said, it is not clear whether the warming by E1 Nino causes a net decrease in the buildup of CO₂ over the long haul. " We don’t really know that yet, " said Schimel. What the study does show, however, is that the rise and fall of CO₂ in the atmosphere is ply influenced by natural changes in global temperature, said B. H. Braswell of the University of New Hampshire, another co-author of the study.
Braswell said that in years when the global weather is cooler than normal, there is a decrease in both the decay of dead plants and in new plant growth. This causes an effect that is the opposite of E1 Nino warming: CO₂ atmosphere levels first decline and later increase.
(50) " I think we have demonstrated that the ecosystem has a lot more to do with climate change than was previously believed," said Braswell, " Focusing on the role of human activity in climate change is important, but manmade factors are not the only factors. \

已知等式（2A-7B）x+（3A-8B）=8x+10对切实数x都成立，求A、B的值．

心肌梗死后慢性心力衰竭病人，无任何症状，需要长期服用哪种药物（）

A.血管紧张素转换酶抑制剂

B.螺内酯

C.β受体阻滞剂

D.利尿剂

E.洋地黄

产后三病是指（）

A.大便难

B.病郁冒

C.病呕吐

D.病发热

E.病痉

William Henry Bragg was born at Westward，Cumberland，on July 2,1862.He was educated at Market Harboroagh Grammar School and afterwards at King William’s College，Isle of Man.Elected as a minor scholar of Trinity College，Cambridge，in 1881，he studied mathematics under the well­known teacher，Dr E．J.Routh.He studied physics in the Cavendish Laboratory during a part of 1885，and at the end of that year he was elected to the Professorship of Mathematics and Physics in the University of Adelaide，South Australia.

His research interests dealt with a great many fields and he was skilled at picking up a subject，almost casually，making an important contribution，and then dropping it again.However，the work of Bragg and his son Lawrence in 1913～1914 founded a new branch of science of the greatest importance and significance，the analysis of the crystal structure by means of X­rays.It is true that the use of X­rays as an instrument for the systematic revelation of the way in which crystals are built was entirely due to the Braggs.This was recognized by the award of the Nobel Prize jointly to father and son in 1915.

He was an honorary Doctor of some sixteen universities，and a member of the leading foreign societies.Many other medals and awards were bestowed upon him among which may be mentioned the Rumford Medal in 1916 and the Copley Medal (its premier award) in 1930.

He was the author of many books，including Studies in Radioactivity，X­Rays and Crystal Structure，The World of Sound，Concerning the Nature of Things，Old Trades and New Knowledge，An Introduction to Crystal Analysis，and The Universe of Light.His favorite hobby was golf.After a life of astonishing productiveness，Sir William Bragg died on March 10,1942.

小题1:William Henry Bragg was awarded the Nobel Prize because________.

A．he succeeded in using X­rays to find out the crystal structure

B．he was the first to use X­rays to help to do his experiment

C．he determined to learn everything well and then gave them up

D．he was successful in his research work with the help of his son小题2:According to this passage，William Henry Bragg was interested in all the subjects EXCEPT________.

A．mathematics

B．physics

C．medicine

D．sports小题3:Which one of the following is TRUE according to this passage?

A．Bragg became a professor in the University of Adelaide in 1885.

B．Bragg won the Rumford Medal and the Copley Medal in the same year.

C．Bragg gained great achievements in many fields，including society.

D．Bragg and Lawrence wrote the book X­Rays and Crystal Structure.小题4:Which of the following is the best title for this passage?

A．William Henry Bragg’s Productive Life

B．William Henry Bragg：A Famous Author

C．Bragg and His Son—Two Great Scientists

D．X­rays and the Crystal Structure