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.

41.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

42.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.

43.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

44.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.

45.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.

B

U.S.airlines are seeing a major interruption because of hundreds of flights canceled due to the ash cloud from the Icelandic volcano, but European flight companies will face the biggest losses.

The airline business has been tough: The decline dramatically slowed traffic; February heavy snow forced U.S.airlines to cancel thousands of flights; and now the ashes from the volcano stopped all traffic in and out of northern Europe for days.

"For U.S.flight companies, it’ll be a relatively short-term hit," said Michael Boyd, president of Boyd Group International, an aviation (航空学) consulting firm."We think right now they’re down about $80 million in terms of lost income, and they’re down domestically about 80,000 passengers that would have been flying domestically but aren’t because they can’t get here."

Delta announced that volcano-related interruption grounded about 400 flights until Monday at a cost of $20 million in lost revenues.But compare that to the recent snowstorms, when the airline canceled 7,000 flights and lost $65 million in revenue.

The disruption has created uncertainty for customers, but analysts say U.S.airlines won’t face as many costs as you might think.They are not flying in extra planes to handle the passengers in trouble because, airline analyst Robert Mann said, companies simply don’t have them.

"Airlines run a very lean operation now," Mann said."So, since there are no spare aircraft or crews, the airlines will attempt to maximize loads on every one of their aircraft that do fly.But it may take days, or in some cases a week or so, to get some of these customers to where they want to go."

46.Which negative consequences mentioned in the passage did the disasters cause?

A.coldness, pollution and airlines’ losses

B.airport damage, pollution and slow traffic

C.passenger delay, coldness and airport damage

D.passenger delay, airlines’ losses and slow traffic

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

A.The fewest airplanes will fly the trapped passengers to their destinations.

B.All the customers are sure to be sent to their destinations in time.

C.The U.S.and U.K.airlines suffered the same losses in the natural disasters.

D.The volcano eruption reduced the traffic to and from northern Europe.

48.What does the last paragraph mainly tell us?

A.the troubles that the airlines will face after the ash cloud disappears

B.the measures that the airlines will take to maximize their profit

C.the present situation of the airlines and their plan to deliver the passengers

D.the reasons why the airlines run a fine operation

49.Why will it take a long time for airlines to send the passengers to their different destinations?

A.Because the passengers enjoy staying in airports to talk with one another.

B.Because the airlines don’t have spare planes or employees to serve.