1、
Have you ever wondered how and why a fall leaf changes color? We first have to understand what leaves are and what they do.
Plants are the world’s food factories. Plants take water from the ground and take CO2 from the air. Plants use sunlight to turn water and CO2 into glucose(葡萄糖). Glucose is a kind of sugar. Using it as food, plants get energy and grow. Plants using sunlight to turn water and CO2 into sugar is called photosynthesis(光合作用). ChlorophyII helps photosynthesis. It gives plants their green color.
As summer ends and autumn comes, the days get shorter and shorter, and trees "know" to begin getting ready for winter. During winter, there is not enough light or water for photosynthesis. Trees rest during this time and live on the food they store during the summer. They begin to shut down their food — making factories. As the green chlorophyII disappears from the leaves, we begin to see yellow and orange leaves. These colors have been in the leaves all the time. We just can’t see them in the summer, because they are covered up by the green chlorophyII.
The bright reds and purples we see in leaves are made mostly in autumn. In some trees, glucose is caught in the leaves after photosynthesis stops. Sunlight and the cool nights of autumn turn this glucose into a red color. The brown color of trees is made from waste left in the leaves. It is mixture(混合物) of all these things. It makes the beautiful leaves during autumn.
根据材料内容选择最佳答案。
【1】The underline word "chlorophyII" in the passage means "_______" in Chinese.
A. 胡萝卜素 B. 叶绿素 C. 氯霉素 D.花青素
【2】When they rest in winter, trees live on the food they store during the_______.
A. summer B. autumn C. winter D. spring
【3】Plants use sunlight to turn_______intosugar.
A.waterandchlorophyII
B. water and CO2
C.CO2 and glucose
D. water and glucose
【4】Which of the following is NOT true according to the passage?
A. Glucose is a kind of sugar and plants use it as food for energy and growing.
B. Leaves turn red because sunlight and the cool nights of autumn turn glucose into a red color.
C. We can’t see yellow or orange leaves in summer because the two colors are not in leaves.
D. During winter, there is not enough light or water for photosynthesis.
【5】What’s the main meaning of this passage?
A. What’s photosynthesis?
B. How and why leaves change colors?
C. Different kinds of leaves.
D.Howtheseasonschange.
【1】B
【2】A
【3】B
【4】C
【5】B
【语篇解读】本文主要讲述了绿色植物在夏天叶子是绿色的而到了秋冬就变色的原因。
【1】B词义猜测题。根据前面的"光合作用"一词,可推断此词意为"叶绿素"。故选B。
【2】A细节理解题。根据文章中第三段的Trees rest during this time and live on the food they store during the summer.可知选A。
【3】B细节理解题。由第二段中的Plants using sunlight to turn water and CO2 into sugar is called photosynthesis(光合作用)可知选B。
【4】C 细节理解题。根据第三段的最后一句We just can’t see them in the summer, because they are covered up by the green chlorophyII可知这才是为什么叶子是到了秋冬就变色的原因,故C选项的表述错误,选C。
【5】B主旨大意题。纵观全文可知本文主要讲述了绿色植物为什么在夏天叶子是绿色的而到了秋冬就变色。结合各个选项的意思可知选B。
- Iwanttomakeacupofmilkshak...
- Alittleboyinvitedhismothe...
- 完形填空。Marywashappytotakeas...
- Don’tmovethedesk_______yo...
- Lisasawthedoctor,butshefe...
- 动词填空(1)--IhaveboughtaChin...
- Heisvery_____thedriver,be...
- Theairpollutioncausedthe_...
- 翻译句子。【1】你去哪里度假?【2】这对我的健康是...
- 阅读下列短文,并根据所读短文内容在文章后的表格里填...
- —Whenwillyouvisityourfrie...
- _____acoldSundayevening,a...
- 阅读理解。DearLinda,Ihavegotyo...
- Growingupisnotalwayseasy....
- —Whatdoyouthinkof_____sho...
- Whendidyou______Hongkong?...
- 口语运用从方框中选择恰当的语句补全对话,有两项是多...
- 句型转换【1】Canyoucomeupwithag...
- 阅读理解Agroupofswansflewdown...
- 任务型阅读。Successisnoteasytot...
- 书面表达伤心的事情无处不在,但是过度伤心会让人生病...
- 完形填空阅读下面的短文,从短文后所给的A、B、C、...
- Mr.andMrs.Clarkare70years...
- —Haveyoufinishedwritingth...
- He______beveryexcitedtoge...
- Lotsofforeigntraverllersc...
- Wheredidyougo____vacation...
- Before2015,wefinished____...
- Sometimes,Ifinditdifficul...
- —I’mworriedaboutmyschoolg...
- 人教新课标八上英语试卷-Unit2How...
- 江苏省常州市外国语学校初二暑假练习
- 人教八下Unit9SectionBper...
- 外研版八上ModuleUnit单元检测题
- 人教八下Unit测试英语试卷
- 新目标英语八上Unit5单元练习题
- 四川省绵阳关帝中学秋人教新目标八上Uni...
- 人教版八下UnitWhat’sthehi...
- 2016-2017学年上期末考试原创模拟...
- 牛津译林版八上Unit3周检测
- 人教版八下UnitSectionAper...
- 绵阳关帝中学秋人教新目标八上Unit单元...
- 春人教英语八下UnitUnit期末训练题
- 外研版英语八下期中综合测试卷
- 徐州市中考总复习八上Unit单元过关测试...
- 人教八上Unit8Howdoyoumak...
- 秋英语(Goforit)八上Unit课后...
- 四川省绵阳关帝中学秋人教新目标八上Uni...
- 牛津译林版八上UnitGrammar课时...
- 北师大版英语八上UnitHelping单...
- 外研八下Module4Seeingthe...
- 人教八上Unit单元检测题
- 人教版八上Unit习题
- 外研版八上ModuleUnit单元检测题
- 牛津译林版单元测试卷八上Unit6
- 牛津译林版八下UnitComicstri...
- 牛津八上unitEducationale...
- 2015-2016学年山东枣庄薛城区奚仲...
- 仁爱版八上Unittopic同步练习
- 测试卷八年级上第三次月考试卷-《八上英语...
- Tomlikesplaying___footbal...
- _isitfromyourhometoschool...
- Heisilltoday,sohe________...
- Comeon,______you'llbelate...
- It’seasy________chess.A.p...
- Whykeepthem?Peoplekeepdo...
- EnglishStudents’Education...
- 根据句意及首字母提示完成单词【1】Remember...
- 句型转换【1】Thereisatreeintheg...
- 书面表达根据以下提示写一篇描述公园里的人、物、景的...
- MyfriendBoblikestoplay___...
- Readingmorehelps_______le...
- —CanIhelpyou,boy?—Yes.The...
- Weneedtwoapplesandthree__...
- —Wheredidyougoyesterday,R...
- —Whattimeisit?—It’s12o’cl...
- ________yourparentsathome...
- —________didhegolastweeke...
- WangYaniwasbornin1975.Eve...
- Friday,August2nd FineWeha...
- Tomwaseightyearsold.Hewa...
- 根据句意及首字母提示完成句子【1】Doyoumin...
- 根据汉语意思完成句子【1】请远离窗户和重的家具。P...
- 补全对话,每空一词A:Hi,Lucy.B:Hi,B...
- 书面表达周末,你想要为全家准备一顿晚饭,请根据下面...
- Let’s_______afterschool.A...
- Oneoftheboys_______apet.T...
- —________doyoulikeanimals...
- Doyouwant______?A.eatrice...
- Ilike_______,butthisafter...
- 北师大版(同北京课改版)英语七年级下册期中检测题
- 北师大版(同北京课改版)英语七年级下册期末检测题
- 北师大版(同北京课改版)英语七年级下册UnitTh...
- 北师大版(同北京课改版)英语七年级下册UnitSe...
- 北师大版(同北京课改版)英语七年级下册UnitNo...
- 北师大版(同北京课改版)英语七年级下册UnitOn...
- 北师大版(同北京课改版)英语七年级下册UnitDa...
- 冀教版英语九年级全册LessonBeCareful...
- 冀教版英语九年级全册LessonMyHelmetS...
- 冀教版英语九年级全册LessonStayAwayF...
- 冀教版英语九年级全册LessonAccidents...
- 冀教版英语九年级全册LessonStayingSa...
- 冀教版英语九年级全册LessonToChinawi...
- 冀教版英语九年级全册LessonDon’tSmok...
- 冀教版英语九年级全册LessonWritingaP...
- 冀教版英语九年级全册LessonJane’sLuc...
- 湖南省长沙市雅礼教育集团八年级上学期期末英语试卷
- 冀教版英语九年级全册LessonChina’sMo...
- 冀教版英语九年级全册LessonGoodFoodG...
- 冀教版英语九年级全册LessonNeverCatc...
- 冀教版英语九年级全册LessonAUniverse...
- 冀教版英语九年级全册LessonAVisittot...
- 冀教版英语九年级全册LessonTouchtheW...
- 冀教版英语九年级全册UnitStayHealthy...
- 冀教版英语九年级全册UnitLesson课时练习
- 冀教版英语九年级全册UnitLesson同步测试卷
- 冀教版英语九年级全册UnitLesson课时练习
- 冀教版英语九年级全册UnitLesson同步练习
- 冀教版英语九年级全册UnitLesson课时练习
- 冀教版英语九年级全册UnitGreatPeople...