Each year red-winged blackbirds stop in a certain region of Midland Province on their spring and fall migrations.  In the fall, they eat a significant portion of the province’s sunflower crop.  This year Midland farmers sought permits to set out small amounts of poisoned rice during the blackbirds’ spring stop in order to reduce the fall blackbird population.  Some residents voiced concern that the rice could threaten certain species of rare migratory birds.  Nevertheless, the wildlife agency approved the permits.

Which of the following, if true, most helps to justify the wildlife agency’s approval of the permits, given the concerns voiced by some residents?

1. In the region where the red-winged blackbirds stop, they are the first birds to be present in the spring.

2. The poison that farmers want to use does not kill birds but rather makes them incapable of producing viable eggs.

3. Since rice is not raised in Midland Province, few species of birds native to the province normally eat rice.

4. Without the permit, any farmers shown to have set out poison for the blackbirds would be heavily fined.

5. The poison that farmers got approval to use has no taste or smell that would make it detectable by birds.

这题不懂啊，NN给讲讲吧，答案是A

我试着答一下, 供参考.(本人很菜,不是nn)

本地居民的反对基于 poisoned rice很可能被其他珍惜的迁徙的鸟类吃掉,威胁到这些

鸟类的生存.

而A选项说the red-winged blackbirds 是每年春天第一批飞到本地的鸟. 结合

到"small amounts of poisoned rice", 等其他鸟类飞到的时候,这些毒大米已经被

blackbirds吃光了,因此不会威胁其他鸟类的生命.

B选项说这些毒会始鸟类产下"不合格"的蛋, 一样会威胁鸟类的生存

C选项说本地鸟类不吃毒大米, 本地鸟类和迁徙的鸟类无关, 因此排除

D说未经许可投毒会受到重罚, 无关.

E说毒药无色无味, 杀鸟于无形, 可怕.....

因此答案是A.