When oceanic islands are far enough apart to permit populations to evolve inisolation, but close enough to allow occasional dispersions to occur, they are effectivelyoutdoor laboratories of evolution. The Galapagos islandchain is one of the world’s greatest showcases of evolution. Each islandwas born from underwater volcanoes and was gradually covered by organisms derivedfrom strays that rode the ocean currents and winds from other islands and continents.
Paragraph 5 supports theidea that Galapagos island chain was able to become one of world’s greatest showcases of evolution primarily because of”
A. the richness of the volcanic soil of each of the islandsin the chain
B. the distance of the individual islands from each otherand from the mainland
C. the relativity long time it took for the islands to becomecovered by organisms
D. the outdoor laboratories that scientists have built onthe islands to study evolution
// 数 字 定 位
The coastal hypothesis has gained increasing support in recent years becausethe remains of large land animals, such as caribou and brown bears, have been foundin southeastern Alaska dating between 10,000 and 12,500 years ago. This is the timeperiod in which most scientists formerly believed the area to be inhospitable forhumans. It has been suggested that if the environment were capable of supportingbreeding populations of bears, there would have been enough food resources to supporthumans. Fladmark and other believe that the first humancolonization of America occurred by boat along the Northwest Coast during the verylate Ice Age, possibly as early as 14,000 years ago. The most recent geologicevidence indicates that it may have been possible for people to colonize ice-freeregions along the continental shelf that were still exposed by the lower sea levelbetween13,000 and 14,000 years ago.
According to paragraph5, the most recent geologic research provides support for a first colonization ofAmerica dating as far as back as
A）16000 years ago
B）14000 years ago
C）12500 years ago
这道题目是答案里出现数字，通过答案的数字直接定位到文章，A答案16000，文章里没有，暂时先放一下，14000在文章出现的地方有两个。关键句在文章里已标注。First human colonization应该可以追溯到14000年之前。所以应该是B。
All this applies, of course, only toan adult leatherback. Hatchlingsare simply too small to conserve body heat, even with insulationand countercurrent exchange systems. We do not know how old, or how large, a leatherback has to be before it canswitch from a cold-blooded to a warm-blooded mode of life. Leatherbacks reach theirimmense size in a much shorter time than it takes other sea turtles to grow. Perhapstheir rush to adulthood is driven by a simple need to keep warm.
According to paragraph 6, which of the following statements is most accurate about young leatherback turtles?
A. They lack the countercurrent exchange systems that develop in adulthood.
B. Their rate of growth is slower than that of other sea turtles.
C. They lose heat easilyeven with insulationand countercurrent exchange systems.
D. They switch between cold-blooded and warm-blooded modes throughout their hatchling stage.
题目里的关键词应该是“young leatherback turtle”，但是回归文章的时候并没有找到。但是“hatchings”（刚孵化的小动物），是跟它相对应的。Hatchings所在的句子是说，刚刚孵化的太小以至于不能去储存热量，即使他们有绝对层跟逆流交换系统。所以同义转换应该是C。
表示原因的词：because/as/blame A for B/account for/due to等
Many millions of years after ferns evolved (but long beforethe Hawaiian Islands were born from the sea), another kind of flora evolved on Earth:the seed-bearing plants. This was a wonderful biological invention. The seed hasan outer coating that surrounds the genetic material of the new plant, and insidethis covering is a concentrated supply of nutrients. Thus the seed’s chances of survival aregreatly enhanced over those of the naked spore. One type of seed-bearing plant, the angiosperm, includes all forms of bloomingvegetation. In the angiosperm the seeds are wrapped in an additional layer of covering.Some of these coats are hard-like the shell of a nut-for extra protection. Someare soft and tempting, like tempting, like a peach or a cherry. In some angiosperms,the seeds are equipped with gossamer wings, like the dandelion and milkweed seeds.These new characteristics offered better ways for the seed to move to new habitats.They could travel through the air, float in water, and lie dormant for many months.
According to paragraph 4, why do seeds have a greater chance of survival than spores do?To receive credit, you must select TWO answer choices.
A. Seeds need less water to grow into a mature plant thanspores do.
B. Seeds do not need to rely on outside sources of nutrients.
C. Seeds are better protected from environmental dangers thanspores are.
D. Seeds are heavier than spores and are therefore more likelyto take root and grow.