（请教）LSAT－2－2－18

18. Learning how to build a nest plays an important part in the breeding success of birds. For example, Dr. Snow has recorded the success of a number of blackbirds in several successive years. He finds that birds nesting for the first time are less successful in breeding than are older birds, and also less successful than they themselves are a year later. This cannot be a mere matter of size and strength, since blackbirds, like the great majority of birds, are fully grown when they leave the nest. it is difficult to avoid the conclusion that they benefit by their nesting experience.

学习如何筑巢是成功生育下一代鸟的重要部分。比如：Dr.Snow连续多年纪录了大量山鸟成功生育的例子。他发现第一年筑巢的鸟在生育小鸟上不如老鸟成功，也不如它们本身几年后成功。 这不仅仅是因为那些鸟的大小和力量的原因，因为山鸟和大多数的鸟类一样，在出巢后就完全成熟了。 所以这个现象很难排出鸟的生育成功率和他们筑巢的经验有关。

Which one of the following, if true, would most weaken the argument?

(A) Blackbirds build better nests than other birds.

(B) The capacity of blackbirds to lay viable eggs increases with each successive trial during the first few years of reproduction.

(C) The breeding success of birds nesting for the second time is greater than that of birds nesting for the first time.

(D) Smaller and weaker blackbirds breed just as successfully as bigger and stronger blackbirds.

(E) Up to 25 percent of all birds are killed by predators before they start to nest.

答案是B,题干没看明白，，请NN解释

concong 发表于 2004-11-15 11:31
18. Learning how to build a nest plays an important part in the breeding success of birds. For examp ...