问题 选择题

一幅图案,在某个顶点处由三个边长相等的正多边形镶嵌而成.其中的两个分别是正方形和正六边形,则第三个正多边形的边数是(  )

A.3

B.5

C.8

D.12

答案

正方形的一个内角度数为180-360÷4=90°,正六边形的一个内角度数为180-360÷6=120°,

∴一个顶点处取一个角度数为90+120=210,

∴需要的多边形的一个内角度数为360-210=150°,

∴需要的多边形的一个外角度数为180-150=30°,

∴第三个正多边形的边数为360÷30=12.

故选D.

阅读理解

BERLIN(AP)—A tiger escaped its enclosure at Cologne Zoo in western Germany on Saturday and killed a female keeper before being shot dead by the zoo’s director,police said.

The tiger slipped through a passage between the enclosure and a neighboring storage building,where it fatally attacked the 43­year­old keeper,said police spokesman Stefan Kirchner.

“It appears the gate wasn’t properly shut,” Kirchner told the Associated Press.

The zoo was evacuated and a SWAT(特警) team was called in,police said.But before it arrived the zoo’s director managed to kill the tiger by climbing onto the storage building and shooting it through a skylight using a rifle.

Kirchner said it was unlikely that members of the public had witnessed the incident.“This is the darkest day of my life,” the zoo’s director,Theo Pagel,was quoted as saying by Cologne newspaper Express.

The paper said on its website that the Siberian tiger was a 4­year­old male called Tltai that came to Cologne Zoo from an animal park in England.In November it fathered three cubs with a 7­year­old Siberian tiger called Hanya,according to the zoo’s website.

Police said the zoo reopened after Saturday’s incident,which occurred around noon.However,a planned late­night opening of the zoo has been canceled.

Cologne Zoo is one of the oldest zoos in Germany.It was founded in 1860 and houses some 10,000 animals comprising more than 700 different species.

小题1:Which of the following can be the best title of the news text?

A.Tiger Escaped,Killed a Keeper in German Zoo

B.Tiger Escaped in German Zoo,Shot Dead

C.German Zoo Keeper Shot Escaped Tiger

D.People Killed in One of the Oldest Zoos in Germany小题2:According to the police,what was the direct reason for the incident?

A.The zoo keeper was a new hand.

B.A gate was not closed appropriately.

C.The zoo had neglected the secret passage.

D.It was very dark when the incident happened.小题3:What did the zoo do after the incident?

A.They honored the killed person in a way.

B.They paid SWAT for their timely help.

C.They returned the tiger’s three cubs to England.

D.They called off the late­night opening.小题4:What can we learn about the Cologne Zoo?

A.It keeps a large variety of species.

B.It is one of the largest zoos in Germany.

C.It has a history of more than 700 years.

D.No such incident has happened before.

单项选择题