还有一个题 Mayor: Migrating shorebirds stop at our beach just to feed on horseshoe-crab eggs, a phenomenon that attracts tourists. To bring more tourists, the town council plans to undertake a beach reclamation project to double the area available to crabs for nesting. Birdwatcher: Without a high density of crabs on a beach, migrating shorebirds will go hungry because shorebirds only eat eggs that a crab happens to uncover when it is digging its own nest. Which of the following, if true, would provide the mayor with the strongest counter to the birdwatcher’s objection? A Every year a certain percentage of crabs are caught by fishermen as bait for eel traps.
B Horseshoe crabs are so prolific that given favorable circumstances their numbers increase rapidly.
C On average, tourists who come to the town in order to watch birds spend more money there than tourists who come for other purposes.
D The additional land made available by the reclamation project will give migrating shorebirds more space.
E Some of the migrating shorebirds make only one stop during their migration form South America to Canada.
Answer: B 来谈谈我的理解，反对者说没有high density，就不能使鸟吃道充足的 uncovered的egg，从而挨饿，用B反对就是crab如此高产，只要是favorable的条件，他就能 繁殖的很多，也就是足够鸟吃的，但我有一个疑问，就是文中并没有肯定是扩大土地 fovorable，还是high density favorable，请达人指点一下，谢谢 | 
