随着我国城乡居民人均可支配收入的增加，一直被视为高档耐用消费品的轿车正悄然走进寻常百姓家。这说明
A．收入是消费的基础和前提B．消费拉动经济增长
C．物价水平影响人们的购买力D．生产与消费相互影响
Until recently most historians believed that trade along the Silk Road .
A. originated in the 2nd century BC
B. extended human migration into eastern Asia
C. began a million years ago
D. primarily benefited the Egyptians
D
Andrew Ritchie, inventor of the Brompton folding bicycle, once said that the perfect portable bike would be “like a magic carpet…You could fold it up and put it into your pocket or handbag”. Then he paused: “But you’ll always be limited by the size of the wheels. And so far no one has invented a folding wheel.”
It was a rare — indeed unique — occasion when I was able to put Ritchie right. A 19th-century inventor, William Henry James Grout, did in fact design a folding wheel. His bike, predictably named the Grout Portable, had a frame. that split into two and a larger wheel that could be separated into four pieces. All the bits fitted into Grout’s Wonderful Bag, a leather case.
Grout’s aim: to solve the problems of carrying a bike on a train. Now doesn’t that sound familiar? Grout intended to find a way of making a bike small enough for train travel: his bike was a huge beast. And importantly, the design of early bicycles gave him an advantage: in Grout’s day, tyres were solid, which made the business of splitting a wheel into four separate parts relatively simple. You couldn’t do the same with a wheel fitted with a one-piece inflated (充气的) tyre.
So, in a 21st-century context, is the idea of the folding wheel dead? It is not. A British design engineer, Duncan Fitzsimons, has developed a wheel that can be squashed into something like a slender ellipse (椭圆). Throughout, the tyre remains inflated.
Will the young Fitzsimons’s folding wheel make it into production? I haven’t the foggiest idea. But his inventiveness shows two things. First, people have been saying for more than a century that bike design has reached its limit, except for gradual advances. It’s as silly a concept now as it was 100 years ago: there’s plenty still to go for. Second, it is in the field of folding bikes that we are seeing the most interesting inventions. You can buy a folding bike for less than ￡1,000 that can be knocked down so small that it can be carried on a plane — minus wheels, of course — as hand baggage.
Folding wheels would make all manner of things possible. Have we yet got the magic carpet of Andrew Ritchie’s imagination? No. But it’s progress.
69. We can infer from Paragraph 1 that the Brompton folding bike .
A. was portable
B. had a folding wheel
C. could be put in a pocket
D. looked like a magic carpet
A. discovered
B. encouraged
C. persuaded
D. supposed
假定原先1台电脑与4部手机的价值量相等，现在生产电脑的社会劳动生产率提高一倍，而生产手机的社会必要劳动时间缩短到原来的一半，其他条件不变，则现在1台电脑与部手机的价值量相等。
A.2B.4C．8D．16