未知题型 我们必须立足优化产业结构推动发展，把调整产业结构作为推动发展的主线，优化产业结构要

未知题型 Red Meat Links to Higher Risk of Breast Cancer Exercise and keeping a healthy weight are two things that doctors say might help women lower their risk of breast cancer. Mothers may reduce their risk if they breastfeed for at least four months. For older women, hormone replacement therapy can lower the risk of some other diseases. But it has been found to increase the risk of breast cancer. So women should consider their choices carefully. The same may be said for diet. New findings show that younger women who eat a lot of red meat have higher rates of breast cancers called hormone-receptor positive. The growth is fed by the levels of estrogen or another hormone, progesterone, in the body. Researchers at Brigham Women's Hospital in Boston, Massachusetts, reported the findings as part of a health study of nurses. The researchers followed the health of more than 90,000 women from 1991 to 2003. Those who ate the most red meat ate more than one and one-half servings a day. A serving was defined as roughly 84 grams. Those who ate the least red meat ate less than three servings a week. This is what the study found about breast cancers that were hormone receptor-positive: The women who ate the most red meat were almost two times as likely to get them as the women who ate the least of it. Eunyoung Cho, the lead author of the report, says more research is needed to know the reason for the link. But in the past, researchers have suggested that three things may play a part. One is the way meat is cooked or processed. Another is the use of growth hormones in cows. And the third is the kind of iron in red meat. The study appears in the Archives of Internal Medicine. And now we have more to tell you about our subject -- resveratrol. We discussed a study in the United States that found that large amounts of this plant compound helped fat mice live longer. The mice were fed much more resveratrol than people could get from red wine, one of the foods that contains it. Now, scientists in France say resveratrol also improves muscle performance -- again, at least in mice. They were able to run two times as far in laboratory treadmill tests4 as mice normally could. The study at the Institute of Genetics and Molecular and Cellular Biologys appeared in the journal Cell.Breastfeeding helps women prevent the development of breast cancer to a certain degree.A．RightB．WrongC．Not mentioned

未知题型 Egypt Felled by FamineEven ancient Egypt's mighty pyramid builders were powerless in the face of the famine that helped bring down their civilisation around 2180 BC. Now evidence gleaned from mud deposited by the River Nile suggests that a shift in climate thousands of kilometres to the south was ultimately to blame -- and the same or worse could happen today.The ancient Egyptians depended on the Nile's annual floods to irrigate their crops. But any change in climate that pushed the African monsoons southwards out of Ethiopia would have diminished these floods.Dwindling rains in the Ethiopian highlands would have meant fewer plants to stablise the soil. When rain did fall it would have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment from the White Nile4.The Blue Nile mud has a different isotope signature from that of the White Nile. So by analysing isotope differences in mud deposited in the Nile Delta, Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river.Krom reasons that during periods of drought, the amount of the Blue Nile mud in the river' would be relatively high. He found that one of these periods, from 4,500 to 4,200 years ago, immediately predates the fall of the Egypt's Old Kingdom.The weakened waters would have been catastrophic for the Egyptians. 'Changes that affect food supply don't have to be very large to have a ripple effect in societies,' says Bill Ryan of the Lamont Doherty Earth Observatory in New York.Similar events today could be even more devastating, says team member Daniel Stanley, a geoarchaeologist from the Smithsonian Institution in Washington, D.C. 'Anything humans do to shift the climate belts would have an even worse effect along the Nile system today because the populations have increased dramatically.'Why does the author mention 'pyramid builders'?A．Because they once worked miracles.B．Because they were well-built.C．Because they were actually very weak.D．Because even they were unable to rescue their civilisation.