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Passage Two
Questions 26 to 30 are based on the following passage.
Ever since Darwin¡¯s theory of evolution, biologists have assumed that environments teeming with complex forms of life served as the nurseries of evolution. But two recent papers in Science magazine have turned that notion on its head. Last month some biologists reported that in the ocean it is the relatively barren areas that serve as ¡°evolutionary crucibles(ÈÛ¯),¡± not regions with great diversity of species. Other researchers announced this summer that the Arctic, not the rain forest, spawned many plants and animals that later migrated to North America. Says John Sepkoski of the University of Chicago, ¡°Harsh environments may be producing the major changes in the history of life.¡±
These ¡°changes¡± do not result merely in a longer tail or a bigger claw for an existing species but, rather, in dramatic leaps up the evolutionary ladder¡ªa rare innovation that comes along once in a million years. In the Arctic, reports Leo Hickey of Yale University, the innovations ran to forms never before seen on earth. By dating fossils from many geologic layers, he concluded that large grazing animals first appeared in the Arctic and migrated to temperate places a couple of million years or so later. Among plants, species of redwood and birch originated in polar regions some 18 millions years before they showed up in the south. Examining fossils as old as 570 million years, Chicago¡¯s Sepkoski found that shell-less, soft-bodied creatures were suddenly replaced by trilobites£¨ÈýÒ¶³æ£©, then by the more advanced clam-like animals. These changes, he notes, ¡°first become common near shore.¡± That surprised him¡ªan environment with as few species as exist in the near shore, and with such a poor record of producing new species, seems an unlikely place for biological innovation. But when Jablonski dated fossils of 100 million years ago, he found that during this era, too, the near shore spawned biological breakthroughs¡ªmore sophisticated sea creatures that move and find food in ocean sediments instead of passively filtering whatever floats by.
The findings are too new to apply to human evolution, but at first glance they seem to fit the facts. Anthropologists believe that our ancestors became fully human only after they left their secure life in the trees for the harsh world of savanna(plain without trees). There, the demanding conditions triggered that most human of traits, the large brain, and the most profound evolutionary step of all was taken.
26. Two recent papers in Science magazine claim to have found evidence which contradicts the traditional notion that          .
A) relatively harsh environments are the nurseries of evolution
B) evolution occurred in regions with biological diversity
C) new forms of life come into being in near-shore areas
D) species of birch and redwood originated in the south
27. According to Leo Hickey of Yale University, which of the following may have spawned more advanced species of land animals?
A) The barren ocean floor.B) The Arctic.
C) The rain forest.D) Temperate Zones.
28. The word ¡°innovations¡± in the second paragraph means          .
A) new theoryB) new phenomenonC) changesD) new inventions
29. How would anthropologists take the new findings?
A) They would look at them dubiously.
B) They would eagerly apply them to the study of human evolution.
C) They would challenge them, though at first glance they tend to look at them favorably.
D) They would most probably think the new findings fit well into their theory.
30. Which of the following may be an appropriate title of the passage?
A) Darwin¡¯s Theory Modified.B) How Animals Evolve.
C) Evolution in Hard Places.D) Where Did Large Sea Animals Originate.
Passage Three
Questions 31 to 35 are based on the following passage.
   That question ¡°why women live longer than men¡± can be answered at two levels. An evolutionary biologist would tell you that it is because women get evolutionary bonus points from living long enough to help bring up the grandchildren. Men, by contrast, wear themselves out competing for the right to procreate in the first place. That is probably true, but not much help to the medical profession. However, a group of researchers at John Moores University has just come up with a medically useful answer. It is that while 70-year-old men have the hearts of 70-year-olds, those of their female peers resemble the hearts of 20-year-olds.
David Goldspink and his colleagues looked at 250 volunteers aged between 18 and 80 over  two years. All the volunteers were healthy but physically inactive. The team¡¯s principal finding was that the power of the male heart falls by 20-25% between the ages of 18 and 70, while that of the female heart remains undiminished.
     They found that between the ages of 20 and 70, men lose 1/3 of the contractile muscle cells in the walls of their hearts. Over the same period, women lose hardly any. There is a strong link between the number of these cells and the function of the heart. What remains a mystery is why men lose these cells and women do not.
   A previous theory of why women outlive men suggested that the female sex hormone, oestrogen, could have a protective effect on the heart. But Dr. Goldspink dismisses this idea, saying that there is no discernible dropª²off in female heart function after menopause £¨¸üÄêÆÚ£©, when oestrogen £¨´Æ¼¤ËØ£© levels decrease dramatically. However, oestrogen does have a beneficial effect on blood vessels. The study found that blood flow to the muscles and skin of the limbs decreases with age in both sexes. The changes in the structure of the blood vessels occur earlier in men, but women catch up soon after menopause.
   It¡¯s not all bad news for men, though. In a related study, the team found that the hearts of veteran male athletes were as powerful as those of inactive 20ª²yearª²old male undergraduates. But can men really recover lost heart function after a lifetime of inactivity and poor diet? Is it ever too late to start exercising? ¡°I think the answer is no,¡± says Dr. Goldspink. ¡°The health benefits to be gained from sensible exercise are to be recommended, regardless of age.¡± So if you are male and getting on, get on with it