Do you know what a “territory”is? A territory is an area that an animal，usually the male，claims(声称)as its own．Only he and his family are welcome there．No other families 0f the same species(物种)are welcome．Your yard and house are your territory where only your family and friends are welcome．If a stranger should enter your territory and threaten you，you might shout．Probably this would be enough to frighten him away．
If so，you have actually scared the stranger away without having to fight him．A bird does the same thing．But he expects an outsider almost any time，especially at nesting(筑巢) season．So he is screaming all the time，whether he can see an outsider or not This screaming is what we call a bird s song，and it is usually enough to keep an outsider away．
Birds sing loudest in the spring when they are trying to attract a mate and warn others not to enter the territory of theirs．
You can see that birds have a language all their own．Most of it has to do with attracting mates and setting up territories．
56．Some scientists believe that most 0f the time birds’
A．an expression of happiness
B．a way of warning
C．an expression of anger
D．a way of greeting
57．What is a bird s“territory”?
A．A place where families of other species are not accepted．
B．A place where a bird may shout at the top of its Voice．
C．an area for which birds fight against each other．
D．An area which a bird considers to be its own．
58．Why do birds keep on singing at nesting season?
A．Because they want to invite more friends
B．Because their singing helps frighten outsiders away．
C．Because they want to find outsiders around．
D．Because their singing helps get rid of their fears．
59．How does the writer explain birds singing?
A．By comparing birds with human beings．
B．By reporting experiment results．
C．By describing birds daily fife．
D．By telling a bird's story．
B
At one time no one could travel on an English road faster than four miles an hour．That was the law until 1896 A man had to walk in front of a car which could not go faster than the man．At night the man had to carry a red lamp．
Once Charles Rolls brought a car from France to England，but he wanted to drive faster than four miles all hour．In order to have no trouble with the police．he had a talk、with some of the police officers．road．This was a good plan in the country，but not so easy to follow in the busy streets of London．
0ne night Rolls and some friends started from London on their journey to Cambridge．One of the men walked in front with the red lamp，but he walked as fast as he could．The police became