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 of400 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 birth weight 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.
His team also found that high-altitude babies tended to have relatively larger heads compared with their bodies. This is probably because a fetus starved of oxygen will send oxygenated blood to the brain in preference to rest of the body.
Giussani wants to fred out if such babies have a higher risk of disease in later life. People born in La Paz might be prone to heart trouble in adulthood, for example. Low birth weight is a risk factor for coronary (冠状的) heart disease. And newborns with ahigh ratio of head size to body weight are often predisposed to high blood pressure and strokes in later life.
41. What does the new study discover?
A. Babies born to wealthy families are heaver.
B. Women living at high altitude tend to give birth to underweight babies.
C. Newborns in cities are lighter than average.
D. Low-altitude babies have a high risk of heart disease in later life.
42. Gussani and his team are sure that
A. babies born in La Paz are on average lighter than in Santa Cruz
B. people living at high altitudes tend to give birth to under-weight babies
C.. the birth weigh of babies born to wealthy families in Santa Cruz
D. mothers in La Paz are commonly under-nourished
43. It can be inferred from what Gussani says in Paragraph 4 that __________ .
A. the finding was unexpected
B. he was very tired
C. the study took longer than expected
D. he was surprised to find low-income families in La Paz
44. The results of the study indicate the reason for the under-wight babies is __________ .
A. lack of certain nutrition
B. poverty of their mother
C. different family backgrounds
D. reduction of oxygen levels
45. It can be learned about from the last paragraph that __________ .
A. high-altitude babies tend to have high blood pressure in later life
B o under-weight babies have a shorter life span
C. babies born to poor families lack hormones before birth
D. new born wealthy families have larger heads compared with their bodies
42.A。细节题。题干：Gussani和他的团队确定的是__________ 。利用题干关键词Gussani and his team和sure可以定位到第四段的首句，可知“足够确定的是，Gussani发现La Paz地区婴儿出生时的平均体重与Santa Cruz相比有着显著的减轻”，所以该题正确答案为A(出生在La Paz的婴儿比出生在SantaCruz的婴儿平均体重轻)。.
43.A。细节题。题干：根据第四段Gussani所说，可以推断出__________。利用题干关键词Gussani says in Paragraph 4可以定位到第四段，从中可知“我们对这个结果感到很吃惊”，所以推知结果是意料之外的，故该题答案为A(发现是意料之外的)。
44.D。细节题。题干：研究结果表明造成婴儿体重不达标的原因是__________。利用题干关键词result ofthe study和reason等可以定位到第五段，可知“研究结果表明出生在高纬度的婴儿在出生前被剥夺了氧气(呼吸较少的氧气)”，由此不难得出该题的答案为D(氧气的减少)。