6、For most pregnant women, exercise is the last thing on their minds．After all, keeping slim while you’re expecting isn’t exactly the top priority— rather, it’s making sure your baby gets enough nutrients to grow．But in a small new study, researchers at the University of Auckland in New Zealand report that a mother’s regular aerobic exercise may be good for a growing fetus’ health — and may even help a baby get a healthier start in life．

The finding is a bit surprising, because exercise is known to lower the risk of insulin resistance（胰島素抵抗），a condition eventually leading to diabetes（糖尿�。�．Although insulin resistance is a detriment in healthy adults, it turns out to be helpful for proper fetal（胎兒）development．In pregnant women, this condition means nutrients get shunted to the growing baby．

The question is: could a mother’s exercise put her developing baby’s food supply at risk? Past studies looking at the effect of exercise on birth weight have been inconclusive, and none have really investigated the influence of exercise on the mother’s sensitivity to insulin．So the University of Auckland’s Dr．Paul Hoffman and his team decided to study 84 first-time mothers, who were of normal weight on average, and track any effects aerobic exercise（有氧運(yùn)動） might have on their insulin sensitivity and, ultimately, on their babies’ birth weight．Researchers asked some women to exercise on a stationary bicycle for at least 40 minutes per session, up to five times each week, starting in the 20th week of pregnancy; the other women were not specifically asked to exercise．When the two groups and their babies were compared, the team found that women who bicycled regularly gave birth to babies who were on average 150g lighter than those born to the non-exercising mothers．In both groups, however, the babies were of healthy weight, and there was no difference in the mothers’ weights．

Generally speaking, babies on the lower end of the normal weight range are considered healthier and less prone to developing diabetes and obesity than heavier ones, so this was an encouraging result．Even more reassuring was that regular exercise did not seem to affect the flow of nutrients to the growing babies in the womb．

1．According to the new study, a pregnant woman’s regular exercise may _______．

      A．bring benefits to a baby’s growth

      B．lower the risk of insulin resistance

      C．put her baby’s food supply at risk

      D．help her keep slim and healthy

2．What does the underlined word “detriment” mean in the second paragraph?

      A．Something that brings good．             B．Something that brings damage．

      C．Something that brings obstacles．       D．Something that brings development．

3．What is the purpose of the experiment carried out by Dr．Paul Hoffman?

      A．To investigate the influence of exercise on pregnant women．

      B．To find out what aerobic exercise can benefit a baby’s growth．

      C．To make sure of the effects exercise may have on babies’ birth weight

      D．To compare the differences between mothers who exercise and who don’t

4．Which of the following statements is true according to the passage?

      A．Lighter babies are generally believed to be healthier than heavier ones．

      B．Non?－exercising mothers will definitely give birth to heavier babies．

      C．No studies have looked at the effect of exercise on birth weight before．

      D．Some women studied were asked to exercise regularly while some don’t．

5．Which of the following may be the best title for the passage?

      A．All mothers should take aerobic exercise．

       B．Moms who exercise give birth to lighter babies。

      C．Exercise reduces the risk of insulin resistance．

      D．Heavier babies are more likely to develop diabetes．