德国著名的经济学家韦伯，创立了工业区位理论。该理论假定只考虑运输因素，则工厂应建

As is reported, it is 100 years______Qinghua University was founded.

A．when 　

B．before

C．after

D．since

女，20岁。四肢无力3d，视物不清1d。1周前有腹泻，持续1d即愈。体检：神志清楚双眼向两侧注视均轻度受限，露白约2.5mm。四肢肌力4级，腱反射近乎消失，指鼻试验不准，跟膝腱试验欠稳，深浅感觉存在，病理反射阴性。该患者最可能是（）

A.面神经炎

B.重症肌无力

C.Miller-Fisher综合征

D.急性小脑炎

E.肌营养不良

棉、麻粉尘属于( )。

A．无机性粉尘

B．有机性粉尘

C．混合性粉尘

D．分散粉尘

In the past year, a lot has changed in the field of human spaceflight. (46)In January, President George Bush brushed aside the fact that America’s entire space-shuttle fleet was grounded when he announced grandiose plans to put people back on the moon, and then to launch a manned mission to Mars. (47) In June, Burt Rutan, an American aeronautical engineer, showed that human spaceflight was no longer the preserve of governments by sending a man to the edge of space in Space Ship One, a privately financed vehicle that cost about the same to build as a luxury yacht. That was followed in September by Sir Richard Branson, the British entrepreneur behind the Virgin brand, announcing that he had signed a deal with Mr. Rutan to work on plans for a fleet of five suborbital vehicles developed from Space Ship One.

(48) Now, in the dying days of the year, America’s Congress has passed a bill that unravels a tangle about who would be responsible for regulating the fledgling industry, and under what terms. (49) The bill also allows passengers to fly, on the understanding that this new generation of vehicles may not be as safe as taking a commercial flight between, say, New York and London.

The official line from Virgin Galactica, as Sir Richard’s latest venture is modestly named, is that this coming change in the law makes no practical difference to the firm’s plans, since they do not intend to fly unless they can make their spacecraft as safe as a private jet. But it must surely come as some sort of relief. In any case, Will Whitehorn, director of corporate affairs at Virgin’s headquarters in London, and soon to become the president of Virgin Galactica, says that work is under way on a mock-up of the interior of a new spacecraft that will hold five passengers. (50) Virgin has already committed $20m towards licensing the SpaceShipOne technology from Mr. Rutan and his financial backer Paul Allen, a software billionaire.

(47) In June, Burt Rutan, an American aeronautical engineer, showed that human spaceflight was no longer the preserve of governments by sending a man to the edge of space in Space Ship One, a privately financed vehicle that cost about the same to build as a luxury yacht.

Research on animal intelligence always makes us wonder just how smart humans are. (1) the fruit-fly experiments described by Carl Zimmer in the Science Times. Fruit flies who were taught to be smarter than the average fruit fly (2) to live shorter lives. This suggests that (3) bulbs burn longer, that there is a(n) (4) in not being too bright.

Intelligence, it (5) , is a high-priced option. It takes more upkeep, burns more fuel and is slow (6) the starting line because it depends on learning — a(n) (7) process — instead of instinct. Plenty of other species are able to learn, and one of the things they’ve apparently learned is when to (8) .

Is there an adaptive value to (9) intelligence That’s the question behind this new research. Instead of casting a wistful glance (10) at all the species we’ve left in the dust I.Q.-wise, it implicitly asks what the real (11) of our own intelligence might be. This is (12) the mind of every animal we’ve ever met.

Research on animal intelligence also makes us wonder what experiments animals would (13) on humans if they had the chance. Every cat with an owner, (14) , is running a small-scale study in operant conditioning. We believe that (15) animals ran the labs, they would test us to (16) the limits of our patience, our faithfulness, our memory for locations. They would try to decide what intelligence in humans is really (17) , not merely how much of it there is. (18) , they would hope to study a(n) (19) question: Are humans actually aware of the world they live in (20) the results are inconclusive.

13（）

A.deliver

B.carry

C.perform

D.apply