高中英语 外研版（2019） 选择性必修 第二册习题素材（6份打包）

Unit 5　A delicate world 题组训练(限时40分钟　总分35分) Ⅰ.阅读理解(每题2.5分,共10分) Most birds,in particular,exhibit some degree of patterns and colours.Australia’s zebra finch (斑胸草雀),for example,was so named because of the zebra-like black and white bars on its tail.But it also has many other colours and patterns,from a bright orange bill to fine white spots along its reddish-brown sides.It’s not uncommon to spot the bird in the drier parts of Australia. We tend to suppose all individuals of that species have their spots and bars in the same places.Look closer yet we’ll see that the quantity and design of these patterns vary between individuals.And somehow a bird exhibits a more obvious feather variation.Occasionally,we see one that has larger than usual pale areas of feathers or,more rarely,has lost its normal patterning altogether. Colouration and patterning in all animals are caused by a range of pigments (色素). Melanin (黑色素) is responsible for blacks and browns,and a lack of this pigment can cause a partial or total loss of an individual’s dark patterning.The two main terms that describe these abnormalities are albinism and leucism.Both conditions are genetic and both can lead to a very similar physical appearance.Leucism,however,causes a lack of the pigment cells that produce melanin.But albinism causes the production of melanin to be reduced or absent. Can we distinguish between the two conditions without the help of a cellular biologist Yes.Albino animals have fully unpigmented red eyes.Leucistic animals,on the other hand, never completely lose pigment from the eye,although they can have blue eyes due to a partial loss of pigment. Why don’t we see more albino or leucistic birds Because the lack of melanin reduces the strength and lastingness of the affected birds’ feathers,making them more easily broken. Additionally,the birds’ vision and hearing are negatively affected,making them less able to hunt.The brighter feathers and lack of patterning also make them easier for attackers to see. [语篇导读] 本文是说明文。文章主要讲述了澳大利亚斑胸草雀的颜色和图案,以及色素缺失对鸟类的影响。 (　　)1.What can we learn about Australia’s zebra finch A.It is one of the rarest birds in Australia. B.It is mostly covered with bright orange feathers. C.It acquires its name from its tail colours and patterns. D.It has the same spots and bars in the same places. 【答案】 C 【解析】 细节理解题。根据第一段的第二句可知,斑胸草雀因其尾部的颜色和图案而得名。故选C。 (　　)2.How is the third paragraph developed A.By giving explanations. B.By presenting opinions. C.By setting assumptions. D.By drawing conclusions. 【答案】 A 【解析】 推理判断题。根据第三段内容可知,第三段主要解释了色素对动物颜色和图案的影响,以及白化病和白变的区别,因此,这一段是通过给出解释展开的。故选A。 (　　)3.What can a lack of melanin lead to A.Total loss of patterns. B.Genetically-born abnormalities. C.Darkened feathers. D.Abnormal formation of wings. 【答案】 B 【解析】 推理判断题 ... ...