题目内容
When you watch TV programmes about wild animals, it is amazing to see how an antelope can escape a lion’s attack. In the wilderness, everyone has a stunt(绝技). Even plants have their own ways of fighting off enemies.
Over millions of years of evolution, plants have developed a unique defence system. Chemicals are widely used for survival, By making their leaves, flowers, stems, roots and fruits distasteful or poisonous to predators(食肉动物), plants can fight back.
One such plant is the Gold Wattle tree. British botanist David Cameron has found that when an animal eats the tree’s leaves, the amount of poisonous tannin(丹宁酸) increases in the other leaves. “It’s like the damaged leaves telephoning the others telling them to fight together against the enemy,” he said.
The tree also sends defence messages to neighboring plants by giving out a special smell. Golden Wattle tress in the surrounding 45 meters will get the message and produce more tannin within 10 minutes. Now, if a predator eats too many of the trees’ leaves, it will die.
Every species of plant or tree specializes in the production of a particular set of chemicals. A herbivore(草食动物) that can safely eat the leaves of one tree may be poisoned by its neighbor.
In this way, plants have developed not only individual defence systems, but also shared it with others. This makes it impossible for a single predator to destroy even a small area of forest.
1．According to the passage, which of the following statements about the Golden Wattle tree is NOT correct?
A．It is only poisonous while it is being attacked.
B．It has the ability to warn its neighboring plants of danger.
C．It fights off its enemies by producing poisonous chemicals.
D．An animal that eats too many of its leaves may be poisoned to death.
2．It is impossible for a single predator to destroy even a small area of forest mainly because ___.
A．plants will become poisonous if they are attacked.
B．plants have very good individual defence systems.
C．plants can protect themselves and share their defence systems.
D．plants can give out special smell to fight off their enemies.
3．What does David Cameron mean in paragraph 3?
A．He means that leaves of Golden Wattle trees can speak to each other.
B．He intends to emphasize that the defence system of Golden Wattle is quick and effective.
C．He wants to indicate that the Golden Wattle leaves are very clever.
D．He is explaining how the Golden Wattle tress warn each other when they are attacked.
4．According to the writer, the unique defence system of plants is the result of ______.
A．millions of years of evolution.
B．the tough natural environment.
C．their outstanding poison producing system.
D．large numbers of herbivores in the wilderness.
5．From the passage, we learn that __________.
A．All the plants or trees are poisonous.
B．Every plant or tree produces its particular chemicals.
C．All the plants or trees produce the same chemicals.
D．Every species of plant or tree produces its particular chemicals.
ACBAD
|
阅读下面短文，根据以下要求：1）汉语提示；2）首字母提示；3）语境提示, 在每个空格内填入一个适当的英语单词，所填单词要求意义准确、拼写正确
Do you like friends who can teach you a lot every day ? Books are
s friends because they bring knowledge to us and keep us 76. company through our life. They are so （有价值）that libraries 77.
are built to (存放) them . Almost all great men are lovers 78.
of books.Franklin said that it was books that l him to success 79.
and that he could have achieved nothing w books .Books are the 80.
holders of mankind's ( 经验 ) and imagination .They enable 81.
us to see through the past and predict the .So when you open 82.
a book , you would get into a world you have never been 83.
before . A good book is a good teacher that h you to get 84.
over difficulties .No matter what you are, or old , poor 85.
or rich , books are your devoted friends .Love books and love life .