618北美一战，悲催！放狗。。。

19891015ly

加油~~~没什么好对不起的~~~下次考好了就是了~

camelo777

LZ加油二战肯定成功~！

guaidudu

楼主你说的OG上的那篇阅读是哪篇啊？ 完全没印象了

-- by 会员 wyy3595 (2011/6/19 15:28:40)

Two opposing scenarios,

the “arboreal” hypothesis and


the “cursorial” hypothesis, have


Line traditionally been put forward con-


(5)  cerning the origins of bird flight.


The “arboreal” hypothesis holds


that bird ancestors began to fly


by climbing frees and gliding


down from branches with the


(10) help of incipient feathers: the


height of trees provides a good


starting place for launching flight,


especially through gliding. As


feathers became larger over time,


(15) flapping flight evolved and birds


finally became fully air-borne.


This hypothesis makes intuitive


Sense, but certain aspects are


Troubling. Archaeopteryx (the


(20) earliest known bird) and its


maniraptoran dinosaur cousins


have no obviously arboreal


adaptations, such as feet fully


adapted for perching. Perhaps


(25) some of them could climb trees,


but no convincing analysis has


demonstrated how Archaeopteryx


would have both climbed and


flown with its forelimbs, and there


(30) were no plants taller than a few


meters in the environments where


Archaeopteryx fossils have been


found. Even if the animals could


climb trees, this ability is not


(35) synonymous with gliding ability.


(Many small animals, and even


some goats and kangaroos,


are capable of climbing trees


but are not gliders.) Besides,


(40) Archaeopteryx shows no obvi-


ous features of gliders, such as


a broad membrane connecting


forelimbs and hind limbs.


  The “cursorial”(running)


(45) hypothesis holds that small


dinosaurs ran along the ground


and stretched out their arms for


balance as they leaped into the


air after insect prey or, perhaps,


(50) to avoid predators. Even rudi-


mentary feathers on forelimbs


could have expanded the arm’s


surface area to enhance lift


slightly. Larger feathers could


(55) have increased lift incrementally,


until sustained flight was gradu-


ally achieved. Of course, a leap


into the air does not provide the


acceleration produced by drop-


(60) ping out of a tree; an animal


would have to run quite fast


to take off. Still, some small


terrestrial animals can achieve


high speeds. The cursorial


(65) hypothesis is strengthened by


the fact that the immediate the-


ropod dinosaur ancestors of


birds were terrestrial, and they


had the traits needed for high


(70) lift off speeds: they were small,


agile, lightly built, long-legged,


and good runners. And because


they were bipedal, their arms


were free to evolve flapping flight,


(75) which cannot be said for other


reptiles of their time.就是这篇原题的，一字不漏的，题目都一样！
给个链接大家参照一下。http://forum.chasedream.com/archiver/GMAT_RC/thread-225965-1.html

guaidudu

加油~~~没什么好对不起的~~~下次考好了就是了~

-- by 会员 19891015ly (2011/6/19 19:56:18)

谢谢谢谢！

guaidudu

没事啊，楼主表紧张。关键是要放松，才有好成绩

有没有啥逻辑之类的可回忆……

-- by 会员 沙龙 (2011/6/19 15:05:11)

考完LZ还记得，昨天晚上疯了一晚上，又忘了，对不住猪位啊。。。