更多"A. its detecting powerB. millions o"的相关试题:
[填空题]A its detecting power
B millions of light years away in space
C the location of the VLT
D as an example
E the birth of the earth
F the rotation of the earth
The VLT will allow scientists to see events______.
[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.
[单项选择]For millions of years before the appearance of the electric light, shift work, allnight cable TV and the Internet, Earth’s creatures evolved on a planet with predictable and reassuring 24-hour rhythms. Our biological clocks are set for this daily cycle. Simply put, our bodies want to sleep at night and be awake during the day. Most women and men need between eight and eight and a half hours of sleep a night to function properly throughout their lives. (Contrary to popular belief, humans don’t need less sleep as they age.)
But on average, Americans sleep only about seven and a half hours per night, a marked drop from the nine hours they averaged in 1910. What’s worse, nearly one third of all Americans get less than six hours of sleep on a typical work night. For most people, that’s not nearly enough.
Finding ways to get more and better Sleep can be a challenge. Scientists have identified more than 80 different sleep disorders. Some sleeping disorders are genetic. But many prob
A. sleep for at least eight hours per night
B. believe that we need less sleep as we age
C. adjust our activities to the new inventions
D. be able to predict the rhythms of our biological clocks
