Some plants are so sensitive pollution that they can only survive in a perfectly clean environment. A. from B. with C. against D. to 题目和参考答案——青夏教育精英家教网—

完形填空(Cloze Test)

　　Many of our traditional medicines come from plants that grow wild throughout the world．Folk medicine keeps the health of the body by using medicines taken from surrounding plants since 　　1　　 for making medicine can be 　　2　　 everywhere, one can 　　3　　 folk medicine in any place of the world．They provide the basic ingredients(成分)that were used in the preparation of medicines and remedies(治疗方法)．

　　The practice of folk medicine 　　4　　 all the way back to the time of early man when both man and animal used plants in order to 　　5　　 healthy．It is not 　　6　　, for example, to see an animal suck the sap of some plant after being 　　7　　 by a poisonous snake．　　8　　 animals seem to have their 　　9　　 gift for knowing which plant will 　　10　　 what illness, man probably learned how to 　　11　　 for himself by animal watching．

　　Man 　　12　　 learned other things from animals．He observed that wild animals when sick remained quiet and rest, depending upon nature's remedies(治疗方法)for 　　13　　 well－the medicine in plants and pure air．He saw that an animal with a 　　14　　 could often be 　　15　　 resting in a cool place, eating nothing and often drinking a lot until the fever was gone．

(1)


[　　]
A．	material
B．	liquids
C．	chemistry
D．	vapour

(2)


[　　]
A．	uncovered
B．	made
C．	found
D．	produced

(3)


[　　]
A．	do
B．	get
C．	complete
D．	practice

(4)


[　　]
A．	comes
B．	goes
C．	reaches
D．	keeps

(5)


[　　]
A．	have
B．	remain
C．	keep up
D．	continue with

(6)


[　　]
A．	usual
B．	uncommon
C．	comfortable
D．	easy

(7)


[　　]
A．	hurt
B．	wounded
C．	eaten
D．	damaged

(8)


[　　]
A．	Unless
B．	However
C．	Even though
D．	Because

(9)


[　　]
A．	native
B．	national
C．	natural
D．	nation

(10)


[　　]
A．	cure
B．	develop
C．	raise
D．	cause

(11)


[　　]
A．	wait
B．	think
C．	long
D．	care

(12)


[　　]
A．	almost
B．	mainly
C．	also
D．	hardly

(13)


[　　]
A．	growing
B．	getting
C．	turning
D．	becoming

(14)


[　　]
A．	disease
B．	wound
C．	fever
D．	cold

(15)


[　　]
A．	watched
B．	found
C．	stared
D．	uncovered

Plants, like animals, are subject to diseases of various kinds．It has been estimated that some 30,000 different diseases attack our economic plants; forty are known to attack corn, and about as many attack wheat．The results of unchecked plant disease are all too obvious in countries which have marginal food supplies．The problem will soon be more widespread as the population of the world increases at its frightening rate．Even in countries which are now amply fed by their agricultural products there could soon be the major crops; the resulting famines(饥荒) could kill millions of people, and the resulting hardship on other millions could cause political upheavals(动乱) disastrous to the order of the world．

Some plants have relative immunity to a great many diseases, while others have a susceptibility to them．A blight (萎菌病) may be but a local infection easily controlled; on the other hand it can attack particular plants in a whole region or nation．An example is the blight which killed virtually every chestnut tree in North America．Another is the famous potato blight in Ireland in the last century．As a result of that, it was estimated that one million people died of starvation and related ailments．

Plant pathologists have made remarkable strides in identifying the pathogens of the various diseases．Bacteria may invade a plant through an infestation of insect parasites carrying the pathogen．A plant can also be inoculated by man．Other diseases might be caused by fungus which attacks the plant in the form of a model or smut or rust．Frequently such a primary infection will weaken the plant so that a secondary infection may result form its lack of tolerance．The symptoms(症状) shown may cause an error in diagnosis, so that treatment may be directed toward bacteria(细菌) which could be the result of a susceptibility caused by a primary virus infection．

How many diseases are known to attack wheat?

A．Around 30000 B．Forty

C．Around 29960 D．Around 40

Unchecked plant disease won't result in_______．

A．food shortages in poor country B．food shortages in rich country

C．increase of world population D．disaster in world politics

What is the main idea of the second paragraph?

A．Some plants have relative immunity to a great many diseases．

B．Some other plants have a susceptibility to a great many diseases．

C．The tolerance of a particular plant changes as the growing conditions change．

D．A blight can be a national infection．

According to the passage, some plant diseases can__________．

A．infect people

B．be prevented by inoculation（接种疫苗）

C．be prevented by killing insects

D．be prevented by improving the growing conditions

Which of the following won’t cause plant disease ?

A．Fungus B．Mold C．Smut D．Rust

Many people say they love birds, but some plant trees _________ some make cages.

A. until B. though C. unless D. while

Like all animal species, plant species must spread their offspring to suitable areas where they can grow and pass on their parents’ genes. Young animals generally spread by walking or flying. Because plants don’t have that ability, they must somehow hitchhike(搭车). Some plant seeds scatter by blowing in the wind or floating on water. Many other plant species, though, trick an animal into carrying their seeds. How do they do this? They enclose the seeds within a tasty fruit and advertise the fruit’s ripeness by its colour or smell. The hungry animal collects and swallows the fruit, walks or flies off, and later spits out the seeds somewhere far from its parent tree. Seeds can thereby be carried for thousands of miles. It may surprise you to learn that plant seeds can resist digestion. In fact, some seeds actually require passage through an animal’s body before they can grow.

Wild strawberries offer a good example of hitchhiking tactics. When strawberry seeds are still young and not yet ready to be planted, the surrounding fruit is green, sour and hard. When the seeds finally mature, the berries turn red, sweet, and tender. The change in the berries’ colour serves as a signal to birds which then eat the strawberries, fly off, and eventually spit out the seeds.

Naturally, strawberry plants didn’t set out with a conscious intention of attracting birds only when their seeds were ready to be dispersed. Nor did birds set out with the intent of planting strawberries. Rather, strawberry plants evolved through natural selection. The sweeter and redder the final strawberry, the more birds spread its ripe seeds; the greener and more sour the young strawberry, the fewer birds destroyed the seeds by eating berries before the seeds were ready.

1．What does the underlined word “dispersed” in the third paragraph mean?

A．spread B．eaten

C．born D．planted

2．For plants, which of the following is NOT a way of spreading their offspring to suitable areas?

A．Hitchhiking. B．Blowing in the wind.

C．Floating on water. D．Tracking an animal.

3．Which strategy does the example of wild strawberries describe?

A．The conscious intent of attracting birds. B．Spreading by walking.

C．Spreading by flying. D．The strategy of taking a lift.

4．Why does the author describe how strawberry seeds are spread?

A．To show plants are good at adapting to the environment. .

B．To show strawberry’s special way.

C．To show the plant has different ways of spreading seeds.

D．To show the mystery of plant.

5．What’s the passage mainly about?

A．How animals disperse offspring. B．How plants disperse their offspring.

C．Plant evolution. D．Plants’ hitchhiking on animals.

Like all animal species, plant species must spread their offspring to suitable areas where they can grow and pass on their parents’ genes. Young animals generally spread by walking or flying. Because plants don’t have that ability, they must somehow hitchhike(搭车). Some plant seeds scatter by blowing in the wind or floating on water. Many other plant species, though, trick an animal into carrying their seeds. How do they do this? They enclose the seeds within a tasty fruit and advertise the fruit’s ripeness by its colour or smell. The hungry animal collects and swallows the fruit, walks or flies off, and later spits out the seeds somewhere far from its parent tree. Seeds can thereby be carried for thousands of miles. It may surprise you to learn that plant seeds can resist digestion. In fact, some seeds actually require passage through an animal’s body before they can grow.