8月2日
错误的，意识中不记得的，没有听清楚的，去掉的
小马分类上-------生物学------第十篇：鸟 2
As we discussed, the human eye has three different types of color resubters(receptors受体) that respond to three basic colors-red, green, and blue
$ H* E% o0 U8 Bor other colors are seem to combinations of these different types of receptors. Birds, however, have receptors for these three basic colors and for outer via light (ultraviolet紫外的)or UV light, thus they have much greater color range, What'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 extremely sensitive to ultraviolet. in one experiment, robins was able to distinguish between two object, one completely unlighted and one leaved(lit)0 F) V* p/ E. r8 _' _5 P
by very beam(dim) UV light. Even with the very dim UV light the object with widely again(was radially aapparent) to the robins. In another experiment female birds works to go(were exposed裸露的) to two male birds. One was behind the shelter transiport(filter过滤的 transparent清楚的) UV light, and one was behind the filter that block the UV light. the female birds preferred the male birds behind the transparent filter; those birds’ betters(feathers) may have appeared more colorful. Hunting birds use UV light to tract down small animals. This is possible because small animals use urine to mark their trials and urine observed the UV light. The hunting birds can use the UV light to follow the trial to their prey.
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feather没听出来~~~！！！！不可原谅！！
