2017年职称英语 考试 报名,2017年职称英语综合C级综合练习十八

　Dangers Await Babies with Altitude
　　Women who live in the world’s highest communities tend to give birth to under-weight babies, a new study suggests. These babies may grow into adults with a high risk of heart disease and strokes.
　　Research has hinted that newborns in mountain communities are lighter than average. But it wasn’t clear whether this is due to reduced oxygen levels at high altitude or because their mothers are under-nourished-many people who live at high altitudes are relatively poor compared with those living lower down.
　　To find out more, Dino Giussani and his team at Cambridge University studied the records of 400 births in Bolivia during 1976 and 1998. The babies were born in both rich and poor areas of two cities: La Paz and Santa Cruz. La Paz is the highest city in the world, at 3.65 kilometers above sea level, while Santa Cruz is much lower, at 0.44 kilometers.
　　Sure enough, Giussani found that the average birthweight of babies in La Paz was significantly lower than in Santa Cruz. This was true in both high and low-income families. Even babies born to poor families in Santa Cruz were heavier on average than babies born to wealthy families in lofty La Paz. "We were very surprised by this result," says Giussani.
　　The results suggest that babies born at high altitude are deprived of oxygen before birth. "This may trigger the release or suppression of hormones that regulate growth of the unborn child," says Giussani.

2017年职称英语综合C级综合练习十八.doc

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