标题: OG12 CR59 急求高人解答~ [打印本页] 作者: shjoiy325 时间: 2011-8-20 16:49 标题: OG12 CR59 急求高人解答~ 59. In order to withstand tidal currents,juvenile horseshoe crabs frequently burrow in the sand. Such burrowing discourages barnacles from clinging to their shells. When fully grown, however,the crabs can readily withstand tidal currents without burrowing, and thus they aquire substantial populations of barnacles. Surprisingly,in areas where tidal currents are very weak,juvenile horseshoe crabs are found not to have significant barnacle populations, even though they seldom burrow.
A. Tidal currents do not themselves dislodge barnacles from the shells of horseshoe crabs.
B. Barnacles most readily attach themselves to horseshoe crabs in aeras where tidal currents are weakest.
C. The strength of the tidal currents in a given location varies widely over the course of a day.
D. A very large barnacle population can significantly decrease the ability of a horseshoe crab to find food.
E. Until they are fully grown,horseshoe crabs shed sheir shells and grow new several times a year.
因为年轻马蹄蟹不断的换壳，这样附着在壳上的barnacles也就没有，这就给出了后一发现的原因。作者: jxgzcly 时间: 2011-8-21 15:21
upstair is great . the concise mainline is that juvenile (to withstand,burrow--> not barnacle) and grown(enable to withstand,not burrow-->barnacles ) exist,but some juvenile in weak current area (not burrow,not barnacle). why ?作者: shjoiy325 时间: 2011-8-21 19:58
灰常感谢~~~作者: yuanxiaoning 时间: 2011-8-26 15:52
谢谢上面解释， 但是又有疑问，根据E的说法，那些fully grown的horseshoe crabs 的壳不是一样会 have significant barnacle populations吗？作者: 朕乃橙子 时间: 2011-8-26 16:11
我也是跑来想问这题 觉得没什么联系=。=结果看见有人在问~上边高人好严密 果然应该注意一些形容词的描述作者: jxgzcly 时间: 2011-8-27 09:14
谢谢上面解释， 但是又有疑问，根据E的说法，那些fully grown的horseshoe crabs 的壳不是一样会 have significant barnacle populations吗？
-- by 会员 yuanxiaoning (2011/8/26 15:52:18)
When fully grown, however,the crabs can readily withstand tidal currents without burrowing, and thus they aquire substantial populations of barnacles. E. Until they are fully grown,horseshoe crabs shed sheir shells and grow new several times a year.作者: aigojackie 时间: 2012-4-13 10:44
请问这题的A选项怎么解释呢？作者: 篮子里的幸福 时间: 2012-7-7 17:14
此题的关键在于juvenile(少年的），之前我不认识这个单词，还以为是螃蟹的一个种类呢……作者: 美人夜带刀 时间: 2012-12-6 21:12
哈哈我和你一样。。。作者: MissUindeed 时间: 2013-6-28 14:57
这题第一次我也错了，后来正确答案就记住了，不能保证这题目如果直接考试我能做对作者: 醒醒Shine 时间: 2014-3-30 20:33
我理了理思路，清晰多了：
关于选项D
无关：非常有诱惑力的选项。但是再仔细看题目的区别，1说的是幼年crabs站不住潮汐只有成年以后才会需要更多的barnacles。2却说的是尽管没有潮汐影响了，幼年crabs还是没有需要更多的barnacles。Why？D的问题是没有对幼年和成年期的区别加以弥补gap，理应排除。