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It is easy for us to tell who our family members are, but do plants recognize(识别) their own family? Some do, scientists say, according to a report by Science News in early 2010.
Guillermo P. Murphy and Susan Dudley are two plant scientists from McMaster University in Hamilton, Canada. They did a few experiments with Jewelweeds, a kind of flower that grows in wet, shady spots. They found that the flowers seem to know their own flower family. In their experiments, Murphy and Dudley planted jewelweeds in pots with either siblings or strangers.
When jewelweeds were planted in pots with strangers, the plants started to grow more leaves than if they had been planted alone. This response(反应)suggests that plants are competing with strangers for sunlight, since a plant with more leaves can receive more light and make more food. Jewelweeds usually grow in the shade, where sunlight is not enough.
When jewelweed seedlings(幼苗)were planted with siblings, they grew a few more branches than they usually would if they were alone – but they did not start growing lots of extra leaves. This behavior suggests the plants are more likely to share resources, rather than compete.
According to the Science News report, Jewelweeds are not the first plants that plant scientists have studied for family recognition. In 2007, Dudley and her team studied the Great Lakes sea rocket, a plant that grows on the beach – where it may be hard to get fresh water. In that experiment, the scientists found that when sea rockets were planted with siblings, they tolerated each other. But when they were planted with strangers, the sea rockets reacted by working extra hard to grow lots of roots.
Dudley says this just because sea rockets, on the beach, get plenty of sun but struggle for water – so when they’re threatened, they compete for water. Jewelweeds have plenty of water but have to compete for sunshine, so they grow more leaves.
【小题1】 What does the underlined word siblings mean?

A.Flowers come from foreign countries.
B.Plants growing in different environments.
C.Flowers planted with lots of strangers.
D.Plants that are the same kind.
【小题2】 In the text, the writer mentioned the experiments of Jewelweeds to         .
A.make a comparisonB.introduce a topic
C.describe a pretty flowerD.build a new theory
【小题3】 According to the passage, flowers planted alone will         .
A.grow more leaves than those planted in groups
B.become taller than those with more branches
C.grow fewer leaves than those planted with strangers
D.become ill easily because they can’t get enough shade
【小题4】 What can be the best title for the passage?
A.New Discoveries about Plants
B.How Plants Compete with Each Other
C.Family Recognition among Plants
D.Jewelweeds and the Great Lakes Sea Rockets

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It is easy for us to tell who our family members are, but do plants recognize(识别) their own family? Some do, scientists say, according to a report by Science News in early 2010.

Guillermo P. Murphy and Susan Dudley are two plant scientists from McMaster University in Hamilton, Canada. They did a few experiments with Jewelweeds, a kind of flower that grows in wet, shady spots. They found that the flowers seem to know their own flower family. In their experiments, Murphy and Dudley planted jewelweeds in pots with either siblings or strangers.

When jewelweeds were planted in pots with strangers, the plants started to grow more leaves than if they had been planted alone. This response(反应)suggests that plants are competing with strangers for sunlight, since a plant with more leaves can receive more light and make more food. Jewelweeds usually grow in the shade, where sunlight is not enough.

When jewelweed seedlings(幼苗)were planted with siblings, they grew a few more branches than they usually would if they were alone – but they did not start growing lots of extra leaves. This behavior suggests the plants are more likely to share resources, rather than compete.

According to the Science News report, Jewelweeds are not the first plants that plant scientists have studied for family recognition. In 2007, Dudley and her team studied the Great Lakes sea rocket, a plant that grows on the beach – where it may be hard to get fresh water. In that experiment, the scientists found that when sea rockets were planted with siblings, they tolerated each other. But when they were planted with strangers, the sea rockets reacted by working extra hard to grow lots of roots.

Dudley says this just because sea rockets, on the beach, get plenty of sun but struggle for water – so when they’re threatened, they compete for water. Jewelweeds have plenty of water but have to compete for sunshine, so they grow more leaves.

1. What does the underlined word siblings mean?

A.Flowers come from foreign countries.

B.Plants growing in different environments.

C.Flowers planted with lots of strangers.

D.Plants that are the same kind.

2. In the text, the writer mentioned the experiments of Jewelweeds to         .

A.make a comparison                      B.introduce a topic

C.describe a pretty flower                  D.build a new theory

3. According to the passage, flowers planted alone will         .

A.grow more leaves than those planted in groups

B.become taller than those with more branches

C.grow fewer leaves than those planted with strangers

D.become ill easily because they can’t get enough shade

4. What can be the best title for the passage?

A.New Discoveries about Plants

B.How Plants Compete with Each Other

C.Family Recognition among Plants

D.Jewelweeds and the Great Lakes Sea Rockets

 

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There is an old saying that all of us are born with two bags hung(悬挂)on our necks. A small bag at the front is filled up with other people's mistakes, while the big one at the back is full of our own shortcomings (短处).

  So it’s easy to find other people's mistakes, but it's hard for us to see our mistakes behind us.

  There was a boy, Tommy, who always opened the front bag to check what was in it. He saw other people's mistakes very quickly. When Simon was impatient with him, he said to Simon, "It's so easy for you to get angry. It is hard to be friends with you."

  He told his mother about Jack's dishonesty. "Jack takes my things without asking. He also forgets to return them." Tommy himself did not like sharing his things with anyone.

  When Johnny was too tired to play with him, he said, "'You are not such a friendly person."

  He thought Harry was too proud of his rich parents. But Tommy was as proud of himself because he could not see any of his own mistakes! He also could not understand why he did not get on well with others.

  If only Tommy would switch(交换)the bags around, he would find his own impatience, dishonesty, bad manners and vanity (虚荣), which were no better than that of Simon, Jack, Johnny or Harry.

(  )66. From the old saying ,we know_______.

A. A small bag in front of our chest. 

B. the big bag at the back

C. It is easy for us to find other people's mistakes than our own mistakes.

D. Two bags hung on our necks.

(  )67. Tommy thought it was hard to be friends with Simon because Simon was _________.

A. impatient  B. a rude person C. dishonest D. too proud of his rich parents

(  )68.Why didn’t Tommy think Johnny was a friendly person?

A. Because Johnny didn’t play with him.

B. Because Johnny was too proud of his rich parents.

C. Because Johnny was dishonesty.

D. Because Johnny did not like sharing his things with anyone.

(  )69. According to the passage, which of the following is TRUE?

A. Tommy was a person liked by others.

B. Tommy liked sharing his things with others.

C. Tommy always discovered his own shortcoming.

D. Maybe Tommy was really no better than Simon, Jack, Johnny or Harry.

(  )70. In this passage, the writer mainly wanted to tell us ________.

A. to be more patient

B. not to be a person with vanity

C. not to take others' things without asking

D. to see our own shortcomings

 

查看习题详情和答案>>

It is easy for us to tell who our family members are, but do plants recognize(识别) their own family? Some do, scientists say, according to a report by Science News in early 2010.

Guillermo P. Murphy and Susan Dudley are two plant scientists from McMaster University in Hamilton, Canada. They did a few experiments with Jewelweeds, a kind of flower that grows in wet, shady spots. They found that the flowers seem to know their own flower family. In their experiments, Murphy and Dudley planted jewelweeds in pots with either siblings or strangers.

When jewelweeds were planted in pots with strangers, the plants started to grow more leaves than if they had been planted alone. This response(反应)suggests that plants are competing with strangers for sunlight, since a plant with more leaves can receive more light and make more food. Jewelweeds usually grow in the shade, where sunlight is not enough.

When jewelweed seedlings(幼苗)were planted with siblings, they grew a few more branches than they usually would if they were alone – but they did not start growing lots of extra leaves. This behavior suggests the plants are more likely to share resources, rather than compete.

According to the Science News report, Jewelweeds are not the first plants that plant scientists have studied for family recognition. In 2007, Dudley and her team studied the Great Lakes sea rocket, a plant that grows on the beach – where it may be hard to get fresh water. In that experiment, the scientists found that when sea rockets were planted with siblings, they tolerated each other. But when they were planted with strangers, the sea rockets reacted by working extra hard to grow lots of roots. 

Dudley says this just because sea rockets, on the beach, get plenty of sun but struggle for water – so when they’re threatened, they compete for water. Jewelweeds have plenty of water but have to compete for sunshine, so they grow more leaves.

1What does the underlined word siblings mean?

A. Flowers come from foreign countries.

B. Plants growing in different environments.

C. Flowers planted with lots of strangers.

D. Plants that are the same kind.

2 In the text, the writer mentioned the experiments of Jewelweeds to         .

 A. make a comparison                       B. introduce a topic

C. describe a pretty flower           D. build a new theory

3According to the passage, flowers planted alone will         .

A. grow more leaves than those planted in groups

B. become taller than those with more branches

C. grow fewer leaves than those planted with strangers

D. become ill easily because they can’t get enough shade

4What can be the best title for the passage?

A. New Discoveries about Plants        

B. How Plants Compete with Each Other

C. Family Recognition among Plants    

D. Jewelweeds and the Great Lakes Sea Rockets

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