下列叙述中，正确的是（ ） ①汽车尾气中的氮氧化物与光化学烟雾的形成有关 ②大量

西北地区的居民和城镇主要呈带状或点状分布的原因是（　　）

A．气候干旱，人们生活在有水源的河流或绿洲地区

B．主要是兰新铁路贯穿了西北地区的大部分

C．主要是资源呈带状或点状分布

D．大部分地区自然地理环境较差，不适合人们居住

桥式脚手架的桥架安装就位后，必须立即固定牢固。桥架搁置在立柱上时，钢销下定要搁在立柱的（）之上，不允许搁在其它位置上。

A．水平杆

B．斜杆

C．立杆

D．脚手板

Charlotte Hollins faces a battle. The 23-year-old British farmer and her 21-year-old brother Ben are fighting to save farm that their father worked on since he was 14. Although confident they will succeed, she is aware of farming’s many challenges.

“You don’t often get a day off. Supermarkets put a lot of pressure on farmers to keep prices low. With fewer people working on farms it can be isolating,” she said. “There is a high rate of suicide and farming will never make you rich!”

Like others around the world, Charlotte’s generation tend to leave the farm for cities.

Oliver Robinson, 25, grew up in Yorkshire. But he never considered staying on his father and grandfather’s land. “I’m sure Dad hoped I’d stay,” he said. “I guess it’s a nice, straightforward life, but it doesn’t appeal to me. For young, ambitious people, farm life is hard.”

For Robinson, farming doesn’t offer much “in terms of money or lifestyle”. Hollins agrees that economic factors stop people from enjoying the rewards of farming. He describes it as a career that provides “for a vital human need”, allowing people to work “outdoors with nature.”

Farming is a big political issue in the UK. The “Buy British” campaigns urge consumers not to purchase cheaper imported foods. The 2001 foot and mouth crisis closed thousands of farms, stopped meat exports, and raised public consciousness about the troubles on UK farms.

Celebrity chef Jamie Oliver’s 2005 campaign to get children eating healthily also highlighted the issue.

This national concern gives hope to farmers competing with powerful supermarkets. While most people buy food from the big supermarkets, hundreds of independent Farmers’ Markets are becoming popular.

“I started going to Farmers’ Markets in direct defiance(违抗) of the big supermarkets. I seriously objected to the super-sizing of everything－what exactly do they put on our apples to make them so big and red? It’s terrible,” said Londoner Michaela Samson, 31.

小题1:What are the challenges that British farmers face according to Charlotte Hollins?

a. loneliness                       b. thin profits

c. a lack of good equipment        d. long working hours but slow results

A．abc

B．abd

C．acd

D．bcd小题2:Why did Oliver Robinson refuse to stay on the farm?

A．He hoped for a simpler life

B．He was fed up with a hard farm life.

C．Farm life was too demanding though he liked it.

D．He hoped for something challenging and rewarding.小题3:What happened in 2001 to the British beef farmers?

A．British people ate more British beef.

B．To be a beef farmer became profitable.

C．Diseaes dramatically reduced the amount of beef available.

D．Foreign farmers stopped selling beef to Britain.小题4:Which of the following is an advantage of Farmers’ Markets?

A．Lower prices.

B．Flexible sizes.

C．Convenient location.

D．Healthier food.小题5:What can we conclude from the last two paragraphs?

A．Things are improving for independent farms in the UK.

B．Farming in the UK can now match the powerful supermarkets.

C．Most British people are doubtful of food in supermarkets.

D．Most British people have realized the problems facing farms and begun to help save them.

生殖细胞减数分裂过程中，细胞内同源染色体分离。向两极移动发生在（）

A.减数分裂前期Ⅰ

B.减数分裂前期Ⅱ

C.减数分裂中期Ⅰ

D.减数分裂后期Ⅰ

E.减数分裂末期Ⅰ

VRML is a (151) for 3D multimedia and shared virtual worlds on the WWW. In comparison to HTML, VRML adds the next level of interaction, structured graphics, and extra (152) (z and time) to the presentation of documents. The applications of VRML are (153) , ranging from simple business graphics to entertaining WWW page graphics, manufacturing, scientific, entertainment, and educational applications, and 3D shared virtual worlds and communities.
X3D is the name under which the development of VRML is continued. X3D is based on XML and is backwards (154) with VRML. Furthermore, it is componentized, profiled, and extensible, which makes it possible to use X3D in very different (155) , from high-end visualizations to lightweight applications.

A．imconsistent

B．independent

C．applicable

D．compatible