Yellow, orange, red and green- tree leaves make autumn a colourful time! Who paints all these colours? It is the leaves themselves. Inside a leaf, there are millions of little colourbags, they are green, yellow and orange. The green ones are called chlorophyll(葉綠素).The yellow ones are called xanthophylls(葉黃素). The orange ones are called carotene(胡蘿卜素).

  In summer, the green chlorophyll is very, very busy. It makes food for the trees. It catches sunlight to change water and carbon dioxide(二氧化碳)into sugar. This sugar is the food for ther tree. It is so busy that it covers up all of the other colours in the leaf.

  When the weather grows colder in autumn, there is less light and water for trees. The trees will have a rest to get ready for winter. They've made enough food in summer! The leaves no longer need water to make food. Without the water, the green chlorophyll starts to go away. The other colours in the leaf-the yellow xanthophylls and orange carotene come out. So the leaves don't reallyturna certain colour. They just lose their green !

  But how about the red, purple and green leaves?

  The leaves look red or purple because they have some sugar in them. Theystealsome food from the tree! The green leaves are from the evergreen trees (常綠樹). The evergreen trees stay green all year long. Their leaves don't lose water in winter.

  Read the passage then choose True(T) or false (F).

(1) The tree leaves have the following colourbags, such as green, yellow and orange except red.

(  )

(2) In summer, the green chlorophyll works hard for the tree leaves.

(  )

(3) In autumn, the tree leaves turn yellow or orange because the green chlorophyll stops working and goes away.

(  )

(4) Tree leaves no longer make food in summer.

(  )

(5) We can infer(推斷)from the article that trees can clean the air.

(  )

練習冊系列答案
相關習題

科目:初中英語 來源: 題型:054

閱讀下列短文,掌握其大意,然后從所給的四個選項中,選出最佳答案

 My cat's  1  is Lucy. She is a very pretty  2  . Her hair is black and yellow.

 She has four children. So I have five  3  . She is very happy with her young  4  .

 The four children are not all  5  Lucy very much. The biggest child is quite black.  6  is black with white feet and one white ear. Two children are like their mother  7  . My daughter says Aren't they pretty?  8  I have the black and white one? Isn't he a tomcat (雄貓)?

 I say I don't know, but I know the yellow and black ones are females (雌性的).”“Are they ? How do you know?”“  9  they are yellow and black. Tomcats never (從不) have that  10  . Listen and I'll tell you ...

                                                                                                                                                     

1Aleg

  

B.family

  

C.house

  

D.name

  

[  ]

  

2Aboy

  

B.dog

  

C.cat

  

D.girl

  

[  ]

  

3Achildren

  

B.cats

  

C.dogs

  

D.brothers

  

[  ]

  

4Ahouse

  

B.family

  

C.home

  

D.baby

  

[  ]

  

5Alike

  

B.by

  

C.love

  

D.with

  

[  ]

  

6AThe other

  

B.Another

  

C.It

  

D.She

  

[  ]

  

7Ayellow

  

B.black

  

C.black and yellow

  

D.white

  

[  ]

  

8ACan

  

B.How

  

C.Do

  

D.Can't

  

[  ]

  

9ASo

  

B.Because

  

C.For

  

D.As

  

[  ]

  

10Ablack

Bfeet

Cear

Dcolour

[  ]

查看答案和解析>>

科目:初中英語 來源: 題型:054

完型填空

  This is my bedroomI can see  1 picture on the wallThe light is  2 the deskThe football is  3 the chair 4 is the bed?it’s near the table

  My father and  5 bedroom is near my bedroom 6 flowers and a bed  7 in their roomSome windows are  8 the wallA yellow door is in the wall,  9 

  I like my bedroom and they like  10 

1

[  ]

Aa   Bone   CI   Dsome

2

[  ]

Aunder   Bon   Cin   Dbehind

3

[  ]

Aon   Bunder   Cto   Dfor

4

[  ]

AWho   BWhat   CWhich   DWhere

5

[  ]

Asister   Bmother   Cmother’s   Dsister's

6

[  ]

AThe   Bthe   CSome   Dsome

7

[  ]

Ais   Bare   Cisn’t   Dam

8

[  ]

Aon   Bbehind   Chere   Dtoo

9

[  ]

Aalso   Bthere   Chere   Dtoo

10

[  ]

Atheir   Btheir’   Cthem   Dtheir room

查看答案和解析>>

科目:初中英語 來源: 題型:閱讀理解

通讀下面短文,掌握其大意,然后在各題所給的四個選項(A、B、C和D)中選出一個最佳選項。

One afternoon, my son Adam asked me, “Are all people the same even if they are different in color?”    I thought for a while, and then I said, “I’ll explain,  31 you can just wait until we make a quick stop at the grocery store. I have something interesting to show you.”

   At the grocery store, we 32 some apples—red, green and yellow ones. Back home, I told Adam, “It’s time to  33 your question.” I put one apple of each type on the table. Then I looked at Adam, who had a  34 look on his face.

“People are like apples. They come in all  35 colors, shapes and sizes. On the  36 , some of the apples may not  37 look as delicious as the others.” As I was talking, Adam was  38 each one carefully.   Then, I took each of the apples and peeled them,  39 them back on the table, but  40 a different place.

  “Okay, Adam, tell me which is which.”

  He said, “I  41 tell. They all look the same now.” “Take a bite of  42 . See if that helps you decide which one is which.”

  He took big bites, and then a huge smile came across his face. “People are  43  like apples! They are all different, but once you  44 the outside, they’re pretty much the same on the inside.”

   He totally  45 it. I didn’t need to say or do anything else.

31. A. although      B. so             C. because       D. if

32. A. bought       B. ate            C. saw       D. found

33. A. check           B. tell                C. answer        D. improve

34. A. worried      B. satisfied         C. proud         D. curious

35. A. usual         B. normal         C. different       D. same

36. A. outside          B. whole          C. table          D. inside

37. A. still          B. even           C. only          D. ever

38. A. examining     B. listening        C. drawing       D. picking

39. A. keeping      B. placing         C. pulling         D. giving

40. A. on          B. towards            C. for         D. in

41. A. mustn’t      B. can’t           C. shouldn’t     D. needn’t

42. A. each one      B. each other       C. the other       D. one other

43. A. just          B. always             C. only          D. never

44. A. put away     B. get down       C. hand out       D. take off

45. A. made         B. took              C. got             D. did

查看答案和解析>>

科目:初中英語 來源: 題型:

One day Mr. Brown saw a young woman in the street with some children. He found all the children__46__ the same — blue coats and yellow trousers. And they each has a white hat on their heads.

“Are you these__47__ mother?” he asked the woman.

“Yes, I am.” she answered. “Do you always dress__48__ in the same clothes? ” asked Mr. Brown.

“Yes,” answered the mother. “ When we have__49__ four children, we let them wear the same clothes because we don’t want to lose__50__ of them. It’s easy to tell our children from__51__ children, and now we have ten children. We__52__ them in the same clothes because we don’t want to take__53__ children home. When there are__54__ children, it is easy to__55__ ours, because their clothes are the same.”                                                                                      

(  )46.A.were looking     B.were wearing       C.were putting on     D.looked like

(  )47.A.children’        B.boys’            C.children’s         D.girls’

(  )48.A.you           B.they             C.their             D.them

(  )49.A.only              B.another           C.more             D.all

(  )50.A.some          B.any              C.an               D.one

(  )51.A.the other B.other C.another D.others

(  )52.A.wear          B.put on            C.dress            D.tell

(  )53.A.our           B.their             C.wrong            D.your

(  )54.A.a little          B.a lot             C.much            D.many

(  )55.A.tell            B.look             C.read             D.look at

查看答案和解析>>

科目:初中英語 來源: 題型:閱讀理解

Different things usually stand for different feelings. Red, for example, is the color of fire, heat, blood and life. People say red is an exciting and active color. They associate(使發(fā)生聯(lián)系) red with a strong feeling like  46 . Red is used for signs of  47 , such as STOP signs and fire engines. Orange is the bright, warm color of  48 in autumn. People say orange is a 49 color. They associate orange with happiness. Yellow is the color of 50. People say it is a cheerful color. They associate yellow too, with happiness. Green is the cool color of grass in 51 . People say it is a refreshing color. In general, people 52 two groups of colors: warm colors and cool colors. The warm colors are red, orange and 53. Where there are warm color and a lot of light, people usually want to be 54. Those who like to be with 55 like red. The cool colors are56 and blue. Where are these colors, people are usually worried. Some scientists say that time seems to 57 more slowly in a room with warm colors. They suggest that a warm color is a good 58 for a living room or a 59 . People who are having a rest or are eating do not want time to pass quickly. 60 colors are better for some offices if the people working there want time to pass quickly.

(  )46. A. sadness     B. anger    C. administration D. smile

(  )47. A. roads      B. ways    C. danger       D. places

(  )48. A. land        B. leaves    C. grass           D. mountains

(  )49. A. lively       B. dark     C. noisy            D. frightening

(  )50. A. moonlight   B. light      C. sunlight      D. stars

(  )51. A. summer        B. spring    C. autumn      D. winter

(  )52. A. speak      B. say      C. talk about        D. tell

(  )53. A. green          B. yellow    C. white            D. gray

(  )54. A. calm       B. sleepy    C. active        D. helpful

(  )55. A. the other       B. another   C. other one        D. others

(  )56. A. black           B. green        C. golden       D. yellow

(  )57. A. go round        B. go by        C. go off        D. go along

(  )58. A. one           B. way      C. fact         D. matter

(  )59. A. factory     B. classroom    C. restaurant        D. hospital

(  )60. A. Different    B. Cool     C. Warm        D. All

查看答案和解析>>

同步練習冊答案