ScienceDaily (May 28, 2010) --- Researchers at Oregon State University (OSU) have made important progress in work that should lead toward robots that can not only walk and run very well, but use little energy at the same time.
Studies are moving closer to designing robots that could do dangerous work, create prosthetic limbs（假肢）for humans that work much better than in the past, or even help some people who use wheelchairs to get “walking” abilities.
“Researchers have been working toward robot movement for a long time,” said Jonathan Hurst, a professor at OSU. “What we’ve done is to study what behavior is really possible for a robot.”
The movement of humans and other animals is difficult to copy. Using little energy, they can move easily over hard areas, and enjoy balance from muscles（肌肉）. They have different ways to deal with forces, such as holding something hard in place rigidly（牢牢地）, like the act of holding a cup of coffee level during a car ride. In their recent studies, the OSU researchers proved that these two abilities are mutually exclusive（相互排斥的）. Humans deal with this problem by using pairs of muscles. For a robot, the more it’s able to do one of these tasks, the less able it is to do the other.
Presently, robots that can walk and run must be as rigid as possible while walking. But this way uses a lot of energy. The OSU researchers are working toward something that has similar or better performance, but uses far less energy, and is closer to the abilities of animals.
“So there’s no reason why we shouldn’t be able to build robots with good movement ability,” Hurst said. “Clearly this might be useful in highly dangerous situations. But I could also see great improvements possible with prosthetic limbs that work much better than present technology. ”
72. The robots being studied by researchers at OSU ______.

A．are successful now

B．use little energy

C．do better than before

D．can run faster than humans

73. Which of the following have researchers been studying all the time?

A．The robots’ movement

B．The robots’ weight

C．The robots’ sizes

D．The robots’ walking speed

74. The underlined words “two abilities” in Para.4 refer to ______.

A．walking and running

B．walking and holding

C．moving and using little energy

D．moving and balancing

75. According to Jonathan Hurst, we know that robots with good movement ability ______.

A．can be used in medical science

B．are only used in highly dangerous situations

C．will hardly be created in the future

D．will have a bad influence on man