问一道来自GWD31套CR分类的第一题

今晚在做GWD31套里的CR分类，发现第一题就有疑问，但是没有给出具体对应那套GWD，导致无法找到讨论贴，：

Q27:

In parts of the Caribbean, the manatee, an endangered marine mammal, has long been hunted for its meat.  Having noted the manatee hunters’ expert knowledge of manatees’ habits, local conservationists are encouraging the hunters to stop hunting and instead to take tourists on boat rides to see manatees.  Tourist interest is high, so the plan has promise of achieving the twin goals of giving the former hunters a good income and helping ensure the manatees’ survival.

Aè
            原文假定旅游者观看marine mammal的兴趣很高

Bè
            原来的捕猎者可以为旅游者通过驾驶船只并找到那些mammals 赚取2倍于原来的收入

削弱：

Which of the following, if true, raises the most serious doubt about the plan’s chance of success?

1. Many tourists who visit these parts of the Caribbean are uninterested in manatees and would not be willing to pay what the former manatee hunters would have to charge for boat rides to see manatees. è
                   攻击前提，错，违背原文

2. Recovery of the species would enable some hunting to continue without putting the manatees’ survival in jeopardy again危险, 危险. 【无关】
3. In areas where manatees have traditionally been hunted for food, local people could easily replace the manatee meat in their diets with other foods obtained from the sea.【不足以削弱】
4. There would not be enough former manatee hunters to act as guides for all the tourists who want to see manatees.【无关】
5. To maintain their current income, manatee hunters who switched to guiding tourists would have to use far larger boats and make many more trips into the manatees’ fragile habitat than they currently do.

我认为应该选A ,即使它攻击的是前提的一个细节，但是该细节非常关键啊。。。E 选项说的我感觉是和捕猎无关的。。。 反而B都有可能啊。。。

可是作者给出答案是E

主要的结论: 这个plan可以ensure manatee's survival

E：far larger boats and make many more trips into the manatees’ fragile habitat 关键词语

大的船只和更多的trip到已经很脆弱的生存环境，会导致manatee更受到危害