10.Anyone who keeps a garden knows that most plants bend towards the sun to catch as much sunlight as they can.This is called"solar tracking".
(36)AIf you observe a sunflower in the early morning,you will find it turning its face eastward; at sunset,on the other hand,its face will turn towards the west.
(37)FIn other words,what happens if you take a sunflower out of the garden bed and keep it in a completely dark room?
Surprisingly,the sunflower will continue its solar tracking without sunlight.It will bend,just as it did outside,eastward at sunrise and westward at sunset,even if there is not a single ray of light inside the dark room.This is a classic example of what scientists call a circadian rhythm (晝夜節(jié)律).What does it mean?(38)DIt's not directed by the environment.
Sunflowers do follow the sun,but they don't just"seek"sunlight.(39)GAlthough sunflowers don't bend with any purpose in mind,some scientists think they have evolved their solar tracking system over millions of years.According to this theory,the evolution helps sunflowers catch light more effectively,and the ones that catch light best are most likely to survive.As a result of this natural selection,we now have sunflowers that bend automatically.(40)EAfter a certain stage sunflowers stop following the sun and only face east.
A.Sunflowers are a well-known example of this.
B.Sunflowers are also an important source of food.
C.Wild sunflowers seen on roadsides don t follow the sun.
D.It is a daily cycle of behavior that is inside of living things.
E.However,that only happens when sunflowers are young plants.
F.But what if there's no sun for the sunflower to guide its solar tracking?
G.This is clear from the fact that sunflowers in darkness bend just as well.
分析 本文屬于說明文閱讀,作者通過這篇文章主要向我們描述了大多數(shù)植物都會朝著太陽彎曲,以盡可能多地捕捉陽光,這就是所謂的"太陽跟蹤"
解答 36.A.推理判斷題.根據(jù)后文If you observe a sunflower in the early morning,you will find it turning its face eastward可知向日葵就是一個很好的例子;故選A.
37.F.推理判斷題.根據(jù)后文In other words,what happens if you take a sunflower out of the garden bed and keep it in a completely dark room可知詢問如果向日葵沒有太陽來指導太陽追蹤呢;故選F.
38.D.推理判斷題.根據(jù)前文This is a classic example of what scientists call a circadian rhythm (晝夜節(jié)律).What does it mean可知它是日�;顒拥难h(huán),是生活的內部;故選D.
39.G.推理判斷題.根據(jù)后文Although sunflowers don't bend with any purpose in mind,some scientists think they have evolved their solar tracking system over millions of years可知從在黑暗中的向日葵彎曲的事實可以明白;故選G.
40.E.推理判斷題.根據(jù)后文After a certain stage sunflowers stop following the sun and only face east可知這是只有當向日葵是年輕的植物發(fā)生的;故選E.
點評 七選五閱讀是完成性閱讀,和完形填空很類似,不同的是一個選詞,一個選句子.解題時,要注意上下文語境,充分考慮信息詞(選項中和空格前后句子中相同或相近的詞),選出最符合語境的句子.