题目内容
________ is the kindness of the nurse that the patient can never be ________ to her.
A. So; too thankful B. Such; too thankful
C. So; that thankful D. Such; enough thankful
B
Plants have family values, too; it seems, with new research suggesting they can recognize close relatives in order to work together.
An ability to tell family from strangers is well known in animals, allowing them to cooperate and share resources, but plants may possess similar social skills, scientists believe.
Susan Dudley and Amanda File of McMaster University in Ontario, Canada, report they have demonstrated for the first time that plants can recognize their kin.
This suggests that plants, though lacking recognition and memory, are capable of complex social interactions.
“Plants have this kind of hidden but complicated social life,” Dudley said.
The study found plants from the same species of beach-dwelling wildflower grew aggressively alongside unrelated neighbors but were less competitive when they shared soil with their families.
Sea rocket, a North American species, showed stronger and healthier root growth when planted in pots with strangers than when raised with relatives from the same maternal(母系的) family, the study found.
This is an example of kin selection, a behavior common in animals in which closely related individuals take a group approach to succeeding in their environment, the researchers said.
Kin selection also applies to competition, because if family members compete less with each other, the group will do better overall. “Everywhere you look, plants are growing right up next to other plants,” Dudley said,“ Usually it’s a case of each plant for itself. But sometimes those plants are related, and there are benefits to not wasting resources on being competitive, and there is not really a cost to not being competitive as long as your neighbor is also not being competitive.”
Learning and memory appear to be important for kin recognition in animals, but this isn’t an option for plants, she noted.
Some researchers speculate(猜测) that plants communicate through their roots, identifying themselves using tiny chemical signatures specific to each plant’s family.
【小题1】What’s the main idea of the message?
A.Studies find plants can recognize, communicate with relatives. |
B.Kin selection is important for plants. |
C.Animals can recognize and memorize their relatives. |
D.Competition asks plants to recognize their relatives. |
A.Animals can recognize and memorize their relatives. |
B.Animals’ social skill is to cooperate and share resources. |
C.Animals’ social skill can recognize close relatives in order to work together. |
D.Animals’ social skill is no use at all. |
A.grow well | B.compete with other kinds of plants |
C.strengthen the relationship among siblings | D.find which one is the best |
A.sea rocket is a South American species |
B.sea rocket grows aggressively alongside unrelated neighbors |
C.sea rocket grows aggressively alongside its siblings |
D.sea rocket is a kind of bush without flowers |
A.Plants communicate by using tiny chemical signatures specific to each plant’s family. |
B.Plants communicate with each other through their roots. |
C.Plants communicate with each other by their leaves. |
D.Plants communicate with each other with their flowers. |