CR一道难题（稍后公布答案）

blvicky

Vervet monkeys use different alarm calls to warn each other of nearby predators, depending on whether the danger comes from land or from the air.

Which one of the following, if true, contributes most to an explanation of the behavior of vervet monkeys described above?

A. By varying the pitch of its alarm call, a vervet monkey can indicate the number of predators approaching.

B. Different land-based predators are responsible for different numbers of vervet monkey deaths.

C. No predators that pose a danger to vervet monkeys can attack both from land and from the air.

D. Vervet monkeys avoid land-based predators by climbing trees but avoid predation from the air by diving into foliage.

E. Certain land-based predators feed only on vervet monkeys, whereas every predator that attacks vervet monkeys from the air feeds on many different animals.

blvicky

这道题是resolve paradox类型的题。但是我怎么看题干，也看不出题干里有什么contradition存在。请高人指点~~

demie

是选E么？

blvicky

是选E么？

-- by 会员 demie (2009/12/12 16:56:18)

不对。所以这题的关键点在知道这是什么题型，然后stimulus里面什么观点是冲突和不同的。

zjqswmm

选D吧~~~ 这种动物为什么要为天上和地上的predator准备两种报警方式呢？ 其实一般一种就够了嘛  题目就是要你解释这个问题

lolmandy

选D吧 同一楼上 不过老感觉题干缺点东西

wordance

Cccccc

onlyloss

IMHO:C

boboinsz

是C吧，刚开始也觉得是D，再想想应该是C。

JNash

应该是D吧？问题要求的是解释。C不是分化警告行为的解释，而是分化警告存在的解释。