[单项选择]

Learning how to fly took nature millions of years of trial and error—but a winged robot has crackedit in only a few hours, using the same evolutionary principles. Krister Wolff and Peter Nordin of Chalmers University of Technology (CUT) in Gothenburg, Sweden, built a winged robot and set about testing whether it could learn to fly by itself, without any pre-programmed data on what flapping is or how to do it.
To begin with, the robot just twitched and jerked erratically. But, gradually, it made movements that gained height. At first, it cheated—simply standing on its wing tips was one early short cut. After three hours, however, the robot abandoned such methods in favor of a more effective flapping technique where it rotated its wings through 90 degrees and raised them before twisting them back to the horizontal and pushing down.
"This tells us that this kind of evolution is capable of coming up with flying motion," says Peter Bentley, who wo
A. Pairing up successful instructions.
B. Sending instructions to the robot.
C. Generating new sets of instructions for evaluation.
D. All of the above.

[单项选择]

Learning how to fly took nature millions of years of trial and error—but a winged robot has crackedit in only a few hours, using the same evolutionary principles. Krister Wolff and Peter Nordin of Chalmers University of Technology (CUT) in Gothenburg, Sweden, built a winged robot and set about testing whether it could learn to fly by itself, without any pre-programmed data on what flapping is or how to do it.
To begin with, the robot just twitched and jerked erratically. But, gradually, it made movements that gained height. At first, it cheated—simply standing on its wing tips was one early short cut. After three hours, however, the robot abandoned such methods in favor of a more effective flapping technique where it rotated its wings through 90 degrees and raised them before twisting them back to the horizontal and pushing down.
"This tells us that this kind of evolution is capable of coming up with flying motion," says Peter Bentley, who wo
A. The winged robot could never really fly.
B. The winged robot did not have a motor.
C. The winged robot should go through further evolution before it could fly.
D. The robot could fly if it were lighter.

[填空题]

Paying for Nature

A. How much are the birds of heaven worth How about the lilies of the field Or clean air and water, verdant forests and untouched grassland, healthy coral reefs and lush mangroves By the environmentalist’s accounting, they’re invaluable because nature has a worth all its own. But to business, untouched nature typically hasn’t had a value—at least not one that could be put in a ledger(账簿).
B. Until now, many green—and a growing chorus of corporate suits—are arguing that nature in its own right provides economically valuable services that benefit business. A virgin forest is pleasant to look at, of course, but it also prevents soil erosion and improves water quality at no cost—valuable if you happen to own a beverage (饮料) plant downstream that depends on clean water. That same forest might provide a habitat for bees, which can pollinate(授粉) plants in the surrounding cropland—a vital f

[单项选择]
Understanding how nature responds to climate change will require monitoring key life cycle event-flowering, the appearance of leaves, the first frog calls of the spring all around the world.
But ecologists can’t be everywhere so they’re turning to non-scientists, sometimes called citizen scientists, for help.
Climate scientists are not present everywhere. Because there are so many places in the world and not enough scientists to observe all of them, they’re asking for your help in observing signs of climate change across the world. The citizen scientist movement encourages ordinary people too observe a very specific research interest--birds, trees, flowers budding, etc. and send their observations to a giant database to be observed by professional scientists. This helps a small number of scientists track a large amount of data that they would never be able to gather on their own. Much like citizen journalists
A. to provide their personal life cycles
B. to observe the life cycle of plants
C. to collect data of the life cycle of living things
D. to teach children knowledge about climate change

[单项选择]Compared with two years ago, how many subscribers has increased
A. 562,500
B. 212,500
C. 25,000

[单项选择]

Understanding how nature responds to climate change will require monitoring key life cycle events—flowering, the appearance of leaves, the first frog calls of the spring—all around the world. But ecologists can’t be everywhere so they’re turning to non-scientists, sometimes called citizen scientists, for help.
Climate scientists are not present everywhere. Because there are so many places in the world and not enough scientists to observe all of them, they’re asking for your help in observing signs of climate change across the world. The citizen scientist movement encourages ordinary people to observe a very specific research interest—birds, trees, flowers budding, etc.—and send their observations to a giant database to be observed by professional scientists. This helps a small number of scientists track a large amount of data that they would never be able to gather on their own. Much like citizen journalists helping large publicat
A. To study when plants will have their first buds.
B. To find out the types of plants in the neighborhood.
C. To collect life cycle data on a variety of common plants from across the United States.
D. To investigate how plants and animals will respond as the climate changes.