题目内容：

    When people think of working animals，what often comes to mind are dogs that watch sheep，horses that work on farms and animals that perform in movies.But there are lots of other jobs animals have had over the years.

Dogs have greater sense of smell than humans.This made dogs the traditional hunting partners，making their owners able to follow foxes and other animals.Police departments have taken advantage of this skill to help find missing people and escaped criminals.Recently，dogs have been trained to find drugs and explosives (爆炸物).

The honey－guide lives in the southeast African nation of Mozambique.It has developed a win－win relationship with a group called the Yao.If a Yao member makes a certain sound，the honey－guide will fly from tree to tree directing him to a hidden bee box.Once the box is discovered，the person breaks open the box for honey，and the honey－guide could enjoy the honey，too.

Ferrets (雪貂) are cute and furry animals that are from 1.5 to 4 pounds.People  have taken advantage of a ferret’s natural ability to run through tiny space.Ferrets wear a special harness(甲胄) that makes them able to pull a string through hundreds of feet of tiny space，which is then used to pull computer wires through tiny space.

Baby flies are called maggots.The job of a maggot is to eat and grow until it turns into a fly.This is similar to how a caterpillar eats and grows until it becomes a butterfly.However，there is a big difference between these insects.Caterpillars feed on plants，while maggots eat meat.Actually，they only enjoy bad meat.Maggots are used with patients who get serious infections that can’t be treated with antibiotics (抗生素).The maggots are used to the infected area for a number of days.They eat the dead part but leave the living part alone，thereby helping patients recover from the infection.

1.From the passage，we can learn that dogs ________.

A.are the friendly friends of sheep

B.have developed a win－win relationship with people

C.have greater sense of smell than foxes and other animals

D.help human beings a lot in many areas

2.With the help of the honey－guide，the Yao member can ________.

A.find the hidden bee box

B.develop a great relationship with bees

C.pay attention to dangerous things

D.stay away from criminals

3.What can we know from the passage?

A.The honey－guide can be used as medicine.

B.People can learn much from dogs and horses.

C.Ferrets are good at running through tiny space.

D.The baby fly is  always called the caterpillar.

4.People can take advantage of the baby flies to treat ________.

A.burns caused by explosives

B.terrible cancers

C.harm caused by bees

D.serious infections