北美4.6回报CD

shallyonline

坐稳貌似是3月JJ哪...我3.26碰到的是同样的.

supsophy

thx! 好棒！

liyanan010

kesha

shallyonline 发表于 2013-4-7 22:15
坐稳貌似是3月JJ哪...我3.26碰到的是同样的.

真的会这样吗，考上月作文？
我刚看AWA，然后27号考试，是不是现在要开始每天练习了？
这篇：错误类比（两个学校的情况不同），无因果（不见得是因为课程少导致的毕业率底）。。还有什么呀？
。。。。。。。亲和lz是怎么写的，求教哈，我刚入门Orz

清早遇到第一个帖子，收货多多，谢lz还有浣熊君

fionayshi

狗主能否回忆一下你的IR答案~~~ 多谢拉！

kiko492

有关羽毛的阅读。有位群里的同学找到疑似原文。请狗主帮忙确认下。谢谢
In his attempt to clarify the phylogenetic tree of theropod dinosaurs, however, Mark has inevitably cast doubt on the common belief that feathers evolved for the sole purpose of flight.

Dave is the best specimen yet to show that feathers existed long before modern birds and flight. But if feathers predated flight, then Mark points out, "we need to come up with another explanation to account for both the presence of feathers in modern birds, as well as their origin in evolutionary time."

This is another scientist's task for another time, but here Mark proposes two hypotheses based upon some evidence from non-avian theropod physiology and modern bird social interaction. First, a highly active, small predator like Dave would have needed a metabolism that allowed him to engage in a high level of activity over a prolonged period of time in order to chase down prey. A metabolism where the metabolic rate is regulated internally by the animal rather than by the outside environment allows this type of activity, but only if little heat is lost to the environment. Dave's body covering of feathers would have been extremely beneficial for insulation purposes to allow him to retain heat and energy. Thus, Mark hypothesizes that feathers originated not for flight, but as an insulation mechanism.

Mark's second hypothesis is that feathers were useful for courtship and other social interactions. Modern male birds often have colored feathers in order to attract a potential mate, and research concludes that many female birds seem to choose a partner based upon certain physical characteristics that indicate a particularly healthy male, such as a bright feather color or elaborate feather display. Thus, feathers could have evolved for reproduction purposes.

Even though Mark has suggested two plausible hypotheses to explain why feathers predated flight, his research does not focus on which, if not both of these, is more likely. Mark's interest and primary research is in filling the gaps in the fossil record of dinosaur evolution.

shallyonline

kesha 发表于 2013-4-8 07:58
真的会这样吗，考上月作文？
我刚看AWA，然后27号考试，是不是现在要开始每天练习了？
这篇：错误类比（ ...

所以我看完就傻了,都看懂了却无从下手.自认为这篇很难,你可以看一下jj,我没有仔细看.貌似逻辑分析得有道理.
我就不误导了,写得乱七八糟.
加油哈!