题目内容
Most animals have 1ittle connection with animals of different kind.unless they hunt them for food.Sometimes,however,two kinds of animals come together in a partnership(伙伴关系) which does good to both of them.You may have noticed some birds sitting on the backs of sheep.This is not because they want a ride,but because they find easy food in the parasites(寄生虫) on sheep.The sheep allow the birds to do so because they remove the cause of discomfort.So although they can manage without each other,they do better together.
Sometimes an animals has a plant partner.The relationship develops until the two partners cannot manage without each other.This is so in the corals(珊瑚) of the sea.In their skins they have tiny plants act as “dustman”,taking some of the waste products from the coral and giving in return oxygen(氧气)which the animal needs to breathe.If the plants are killed,or are even prevented from light so that they cannot live normally(正常地),the corals will die.
1.Some birds like to sit on a sheep because____________.
A.they can eat its parasites
B.they depend on the sheep for existence
C.they enjoy travelling with the sheep
D.they find the position most comfortable
2.The underlined word “they” in last sentence of the first paragraph refers to_____________.
A.birds and parasites
B.birds and sheep
C.parasites and sheep
D.sheep, birds and parasites
3.It can be learnt from the text that the coral depends on the plant for________.
A.comfort B.light C.food D.oxygen
4.What does the second paragraph mainly discuss?
A.Some animals and plants depend on each other for existence
B.Some animals and plants develop their relationship easily.
C. Some plants depend on each other for food.
D.Some animals live better together.
5.What does this article talk about?
A.Two kinds of animals form a partnership.
B. Most animals only have connection with animals.
C.The connection between the living things.
D.Corals have some connection with plants.
ABDAC
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