题目内容
The flying fox is not a fox at all. It is an extra large bat that has got a fox’s head, and that feeds on fruit. Like all bats, flying foxes hang themselves by their toes (趾) when at rest, and travel in great crowds when out flying. A group will live in one place for years. Sometimes several hundreds of them occupy a single tree. As they return to the tree towards sunrise, they quarrel among themselves and fight for the best places until long after daylight.
Flying foxes have babies once a year, giving birth to only one at a time. At first the mother has to carry the baby on her chest wherever she goes. Later she leaves it hanging up, and brings back food for it to eat. Sometimes a baby bat falls to the ground. Then the older ones fly down and try to pick it up. If they fail to do so, it will die. Often hundreds of baby bats can be found lying on the ground at the foot of the tree.
【小题1】The passage tells us that there is no difference between the flying fox and the ordinary bat in ______.
A.their size | B.their appearance |
C.the kind of food they eat | D.the way they rest |
A.double their number every year |
B.fight and kill a lot of themselves |
C.move from place to place very often |
D.lose a lot of their young |
A.fly out toward the sun |
B.look for a new resting place |
C.come back to their home |
D.go out and look for food |
A.to occupy the best resting places |
B.only when it is dark |
C.to protect their homes from outsiders |
D.when there is not enough food |
A.They only care for their own babies. |
B.They share the feeding of their young. |
C.They help when a baby bat is in danger. |
D.They often leave home and forget their young. |
【小题1】D
【小题2】D
【小题3】C
【小题4】A
【小题5】C
解析
At night, bats fly through the air, catching hundreds of insects and other small animals. But during the day, they hardly move at all. Instead, bats pass the time hanging upside down from a secret spot.
There are a couple of reasons why bats rest this way. First of all, it puts them in a position for takeoff. Unlike birds, bats can’t fly into the air from the ground. Their wings don’t produce enough lift to take off from a dead stop, and their hind legs are so small and underdeveloped that they can’t run to build up the necessary takeoff speed. Instead, they use their front claws to climb to a high spot, and then fall into flight.
During the hours when most enemies are active, bats gather where few animals would think to look and most can’t reach. This allows them to disappear from the world until night comes again. There’s also little competition for these resting spots, as other flying animals don’t have the ability to hang upside down.
Bats have a unique physiological adaptation that lets them hang around this way without using any energy. For you to hold your fist around an object tight, you contract(紧缩)several muscles in your arm, which are connected to your fingers by tendons(腱);as one muscle contracts, it pulls a tendon, which pulls one of your fingers closed. A bat’s talons(爪)close in the same way, except that their tendons are connected only to the upper body, not to a muscle. To hang upside down, a bat pulls its claws open with other muscles. To get the talons to take hold of the surface, the bat simply lets its body relax. The weight of the upper body pulls down on the tendons connected to the talons, causing them to hold tight. Therefore, the bat doesn’t have to do anything to hang upside down.
【小题1】Bats hang upside down because________.
A.they haven’t developed a pair of strong claws | B.they can’t start to fly from the ground directly |
C.they have no hind legs to support their body | D.they can’t find quiet places to stay during the day |
A.is to save their energy for night movement | B.is a way to fight against flying animals |
C.is a great way to hide from danger | D.is a skill to compete for the flying places |
A.Because their upper body is light. |
B.Because they have strong muscles. |
C.Because their talons are linked to muscles tightly. |
D.Because their tendons are linked to their upper body. |
A.The living habits of bats. | B.How and why bats hang upside down. |
C.The importance of bats’ hanging upside down. | D.How bats use their energy at night. |