新托福听写训练 第10期

As we've discussed, the human eye has three different types of color receptors that respond three basic colors: red, green, and blue. Or other colors are seem to combinations of these different types of the receptors. Birds, however, have receptors for these three basic colors and for ultraviolet or UV light. Thus they have much greater color range. That's really interesting though, is the role that UV light plays in a bird's life. Scientists have discovered that the bird's eye is very extremely sensitive to ultraviolet light. In one experiment, robins¹ were able to distinguish between two objects. One completely unlit and one lit by very dim ultraviolet light. Even with the very dim UV light, the object was radically²?readily apparent to the robins. In another experiment, female birds were exposed to two male birds. One was behind the filter transparent³ to the UV light, and one was behind the filter that blocked UV light. The female birds preferred the male birds behind the transparent filter. Those birds' feathers may have appeared more colorful. Hunting bird use UV light to track down small animals. This is possible because small animals use urine to mark their trails and urine observed?absorbed UV light. The hunting birds can use the UV light to follow the trail to their prey⁴.

1 robins   

n.知更鸟，鸫( robin的名词复数 )；（签名者不分先后，以避免受责的）圆形签名抗议书（或请愿书）

参考例句：

• The robins occupied their former nest. 那些知更鸟占了它们的老窝。 来自《现代汉英综合大词典》
• Benjamin Robins then entered the fray with articles and a book. 而后，Benjamin Robins以他的几篇专论和一本书参加争论。 来自辞典例句

2 radically   

ad.根本地，本质地

参考例句：

• I think we may have to rethink our policies fairly radically. 我认为我们可能要对我们的政策进行根本的反思。
• The health service must be radically reformed. 公共医疗卫生服务必须进行彻底改革。

3 transparent   

adj.明显的，无疑的；透明的

参考例句：

• The water is so transparent that we can see the fishes swimming.水清澈透明，可以看到鱼儿游来游去。
• The window glass is transparent.窗玻璃是透明的。

4 prey   

n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨

参考例句：

• Stronger animals prey on weaker ones.弱肉强食。
• The lion was hunting for its prey.狮子在寻找猎物。