下图是广州亚运会开幕式中广州塔上正在燃放的焰火，这些五彩缤纷的焰火与元素的焰色反

已知一组数据：1，3，5，5，6，则这组数据的方差是[ ]

A．16      

B．5       

C．4       

D．3.2

简述气质和人格的区别。

异烟肼的鉴别反应用（）

A.地西泮对照品

B.碱性β-萘酚试液

C.氨制硝酸银试液

D.溴化氰试液

E.碘化钾淀粉试纸

The Southdale shopping centre in Minnesota has an atrium, a food court, fountains and acres of parking. Its shops include a Dairy Queen, a Victoria’s Secret and a purveyor of comic T-shirts. It may not seem like a landmark, as important to architectural history as the Louvre or New York’s Woolworth Building. But it is. "oh, my god!" chimes a group of teenage girls, on learning that they are standing in the world’s first true shopping mall. "That is the coolest thing anybody has said to us all day. "

In the past half century Southdale and its many imitators have transformed shopping habits, urban economies and teenage speech. America now has some 1,100 enclosed shopping malls, according to the International Council of Shopping Centres. Clones have appeared from Chennai to Martinique. Yet the mall’s story is far from triumphal. Invented by a European socialist who hated cars and came to deride his own creation, it has a murky future. While malls continue to multiply outside America, they are gradually dying in the country that pioneered them.

Southdale’s creator arrived in America as a refugee from Nazi-occupied Vienna. Victor Gruen was a Jewish bohemian who began to design shops for fellow immigrants in New York after failing in cabaret theatre. His work was admired partly for its uncluttered, modernist look, which seemed revolutionary in 1930s America. But Gruen’s secret was the way he used arcades and eye-level display cases to lure customers into stores almost against their will. As a critic complained, his shops were like mousetraps. A few years later the same would be said of his shopping malls.

By the 1940s department stores were already moving to the suburbs. Some had begun to build adjacent strips of shops, which they filled with boutiques in an attempt to re-create urban shopping districts. In 1947 a shopping centre opened in Los Angeles featuring two department stores, a cluster of small shops and a large car park. It was, in effect, an outdoor shopping mall. Fine for balmy southern California, perhaps, but not for Minnesota’s harsh climate. Commissioned to build a shopping centre at Southdale in 1956, Gruen threw a roof over the structure and installed an air-conditioning system to keep the temperature at 75°F (24℃)—which a contemporary press release called "Eternal Spring". The mall was born.

Gruen got an extraordinary number of things right first time. He built a sloping road around the perimeter of the mall, so that half of the shoppers entered on the ground floor and half on the first floor-something that became a standard feature of malls. Southdale’s balconies were low, so that shoppers could see the shops on the floor above or below them. The car park had animal signs to help shoppers remember the way back to their vehicles. It was as though Orville and Wilbur Wright had not just discovered powered flight but had built a plane with tray tables and a duty-free service.

Which of the following is not the extraordinary thing Gruen got for the first time（）

A. Sloping road around the perimeter of the mall

B. Free shipping services

C.Low balconies of the shops

D. Animal signs in car park

T-P-N动物群与E-E-L动物群T、P、N动物群