Plants may not have eyes and ears，but they can recognize their siblings (兄弟姐妹)，and researchers at the University of Delaware have discovered how.The ID system lies in the roots and the chemical signals they secrete (分泌)．

Canadian researchers published that sea rocket，a common seashore plant，can recognize its siblings.Susan Dudley observed that when siblings are grown next to each other in the soil，they “play nice” and don’t send out more roots to compete.However，the moment one of the plants is thrown in with strangers，it begins competing with them by rapidly growing more roots to take up the water and mineral nutrients in the soil.

After reading Dudley’s study，Bais decided to find the method behind the sibling recognition.Working in his laboratory，Bais and his doctoral student Meredith Biedrzycki set up a study with wild populations of Arabidopsis thaliana.In a series of experiments，young seedlings were exposed to liquid media containing the root secretions from siblings，from strangers，or only their own secretions.The length of the longest lateral (侧面的) root was measured.The exposure of plants to the root secretions of strangers induced (引诱) greater lateral root formation than exposure of plants to sibling secretions.Strangers planted next to each other are often shorter，because so much of their energy is directed at root growth.Because siblings aren’t competing against each other，their roots are often much shallower (浅的)．

Biedrzycki did the painstaking laboratory research，observing more than 3,000 plants involved in the study every day for seven continuous days and documenting the root patterns.“Arabidopsis roots are nearly translucent (半透明的) when they are young and were also twisted when I removed them from plates，”Biedrzycki notes.“This manuscript (手稿) is very important for my research since the focus of my thesis project is understanding the biochemical ways behind root secretions.”

The research also may have implications for the home gardener.“Often we’ll put plants in the ground next to each other and when they don’t do well，we blame the local garden center where we bought them or we attribute their failure to a germ，”Bais says.“But maybe there’s more to it than that.”

1.Which of the following would be the best title for this passage?

A．A Great Biology Researcher

B．Plants Recognize Their Siblings

C．Plants’ Roots and Secretions

D．A Research on Plants

2. What encouraged Bais to study the sibling recognition?

A．Sea rocket.

B．Plants’ sensing system.

C．Biedrzycki’s thesis project.

D．Dudley’s study.

3. What does the underlined word “painstaking” in Paragraph 4 probably mean?

A．Important.? B．Adventurous.

C．Careful.? D．Hard?working.

4.What can we infer from the last paragraph?

A．The local garden center should be blamed when plants can’t grow well.

B．The local garden center often sells low quality seeds to customers.

C．Plants in the home garden can’t grow well because of the germ and seeds.

D．Competing against strangers，plants in the home garden can’t grow well.

 Some myths are stories told since ancient times to explain the causes for natural happenings.

       The Greek myth that explains why there are changes of (36) _______ is about Demeter, the goddess of the harvest．She had a daughter, Persephone, whom she loved very much．Hades, god of the underworld, fell in love with Persephone, and he asked Zeus, the ( 37) _______ of the gods, to give Persephone to him as his (38) _______．Zeus did not want either to disappoint Hades or to upset Demeter, so he said he would not agree to the marriage, but neither would he (39) _______ it．Hades, therefore, decided to take the girl without (40) _______．When Persephone was picking flowers in the garden, he seized her and took her to the underworld．When Demeter (41) _______ what happened to Persephone, she became so (42) _______ that she caused all plants to ( 43 ) _______．People were in (44) _________ of starving．But Demeter was determined not to let crops grow (45 ) _______ her daughter, Persephone, was returned to her．(46) __________, still not wanting to disappoint Hades, decided upon a condition for Persephone's (47) ______ ．She could go back to her mother if she had not (48) ________ anything while she was in the underworld．Demeter (49) ________ it because she did not know that Persephone had eaten several pomegranate (石榴) seeds in the underworld．When Zeus (50) ______ this, he agreed that Persephone could spend part of the year with her (51) _______, but he added that since she had eaten the seeds, she must spend part of the year in the underworld．And so it (52) ________ that when Persephone is in the underworld, Demeter is sad and therefore (53) _______ not let the crops grow．That is (54) ______ we have winter when plants do not grow．When Persephone returns, Demeter is (55)______ , it  is spring, and plants begin to grow again

第二部分：阅读理解（共20题，每小题3分，满分60分）
阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项，并在机读卡上将该项涂黑。
The part of the earth’s history known as the coal age began more than 250 million years ago and lasted millions of years. During that time, in the area that is now the United States, coal beds formed from Texas to the north Atlantic coast.
At that time thick forests swamps（沼泽） covered much of the earth’s surface. Great trees died and fell into the swamps. Then they rotted （腐烂）and new trees and plants grew on top of them. The process repeated itself for thousands of years. The rotted plants turned into a substance called peat（泥炭）, which is still forming today in many swamps.
Meanwhile the land surface was changing. Movement in the earth’s crust (地壳) pushed up hills in some places, while elsewhere land sank. Swift rivers ran from the hills; heavy rains fell and the rivers overflowed, leaving muddy sand in the sunken wooded places and swamps. Oceans, too, poured in over the low-lying land, carrying sand that covered the peaty areas.
The pressure of water and sand pressed the oxygen and hydrogen out of the peat, leaving carbon. Under constant pressure, the rotted material, containing a high percentage of carbon, formed gradually into coal.
56. This main idea of the passage is about the ______.
A. coal beds in the U.S.   B. earth’s history   C. formation of coal   D. swamp age
57. When plants died, they _____.
A. grew up again       B. fell into the water and rotted
C. fell into coal beds    D. turned immediately to coal
58. Hills were formed as a result of _____.
A. movements of the earth’s crust       B. the remaining from swamps
C. the remaining from swift rivers       D. ocean currents
59. What is implied but not stated in the passage?
A. Peat is still forming today.
B. The formation of coal requires high pressure.
C. The land surface changed during the coal age.
D. The formation of coal was very rapid.

Some myths are stories told since ancient times to explain the causes for natural happenings. The Greek myth that explains why there are changes of ___1___ is about Demeter, the goddess of the harvest. She had a daughter, Persephone, whom she loved very much. Hades, god of the underworld, fell in love with Persephone, and he asked Zeus, the ___2___ of the gods, to give Persephone to him as his ___3___. Zeus did not want either to disappoint Hades or to upset Demeter, so he said he would not agree to the marriage, but neither would he ___4___ it. Hades, therefore, decided to take the girl without ___5___. When Persephone was picking flowers in the garden, he seized her and took her to the underworld. When Demeter ___6___ what happened to Persephone, she became so ___7___ that she caused all plants to ___8___ People were in ___9___ of starving. But Demeter was determined not to let crops grow ___10___ her daughter, Persephone, was returned to her. ___11___, still not wanting to disappoint Hades, decided upon a condition for Persephone’s ___12___. She could go back to her mother if she had not ___13___ anything while she was in the underworld. Demeter ___14___ it because she did not know that Persephone had eaten several pomegranate(石榴) seeds in the underworld. When Zeus ___15___ this, he agreed that Persephone could spend part of the year with her ___16___, but he added that since she had eaten the seeds, she must spend part of the year in the underworld. and so it ___17___ that when Persephone is in the underworld, Demeter is sad and therefore ___18___ not let the crops grow. That is ___19___ we have winter when plants do not grow. When Persephone returns, Demeter is ___20___, it is spring, and plants begin to grow again.

1. A. periods   B. seasons       C. time    D. age

2. A. winner   B. ruler   C. advisor       D. fighter

3. A. wife       B. lover   C. partner       D. daughter

4. A. forbid    B. forgive       C. admit  D. accept

5. A. arrangement   B. warning     C. reason D. permission

6. A. let out    B. worked out C. thought out D. found out

7. A. excited   B. tired   C. angry  D. serious

8. A. grow fast       B. start growing     C. stop growing     D. grow slowly

9. A. danger    B. hope   C. turn    D. case

10. A. since    B. until   C. after   D. when

11. A. Persephone   B. Zeus   C. Demeter     D. Hades

12. A. return   B. change       C. marriage    D. journey

13. A. stolen   B. found  C. eaten   D. heard

14. A. understood   B. refused       C. doubted      D. accepted

15. A. discovered   B. studied       C. forgot D. prepared

16. A. daughter      B. mother       C. god     D. ruler

17. A. works   B. remains      C. happens      D. starts

18. A. should  B. can     C. dare    D. will

19. A. where   B. because      C. why    D. how

20. A. nice      B. friendly      C. fresh   D. happy

Plants can’t communicate by moving or making sounds, as most animals do. Instead, plants produce volatile compounds (挥发性化合物) —— chemicals that easily change from a liquid to a gas. A flower’s sweet smell, for example, comes from such volatile compounds to attract insects such as bugs and bees.
Plants can also discover  volatile compounds produced by other plants. A tree under attack by hungry insets, for instance, may give off these chemicals in order to let other trees know about the attack. In response, the other trees may send off their chemicals to keep the bugs away —— or even chemicals that will attract the bugs’ natural enemies.
Now scientists have created a quick way to understand what plants are saying: a chemical sensor (传感器) called an “electronic nose”. The “e-nose” can tell such compounds as plants make. When plants are attacked, scientists say, the e-nose could help quickly decide whether plants are being eaten by insects. But today, the only way to spot such insects is to inspect individual plants by observing them. This is a challenging task for managers of greenhouses, including those that can house thousands of plants. The research team is working with an e-nose that can recognize volatile compounds. Inside the device, 13 sensors chemically react with volatile compounds based on the interactions (相互作用), and then the e-nose will give off electronic signals that the scientists can analyze by using computer software.
To test the e-nose, the team presented it with healthy leaves from cucumber, pepper and tomato plants, all being common greenhouse crops. Then scientists collected samples of the air around damaged leaves from each type of crop. These plants had been damaged either by insects or by scientists who made holes in the leaves with a hole punch (打孔器).
The e-nose, it turns out, can identify healthy cucumber, pepper and tomato plants based on the volatile compounds they produce. It could also identify tomato leaves that had been damaged. But even more impressive, the device could tell which type of damage —— by insects or with a hole punch —— had been done to the tomato leaves.
With some fine-tuning (微调), a device like the e-nose can one day be used in greenhouses to quickly spot harmful bugs, the researchers say. A device like this can also be used to identify fruits that are perfectly ripe and ready to pick and eat, says Natalia Dudareva, a biochemist at Purdue University in West Lafayette, India, who studies smells of flowers and plants. Hopefully, scientists believe, the device can bring large benefits to greenhouse managers in the near future.
【小题1】We learn from the text that plants communicate with each other by ______.