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If a pancake could dream, it might long for legs so it could jump off your breakfast plate in pursuit of a better, unchewed life. But legs aren’t necessary for something as flat as a pancake to jump around. A group of scientists have designed a pancake-shaped robot that can jump several times per second and higher than seven times its body height. The new robot named Hop, which swiftly jumps without feet, is an important contribution to the soft robotics.

Many ground robots move by rolling or walking. But it’s more efficient for robots to jump over obstacles (障碍物) than to go around them. Although jumping can offer some robots a competitive edge, engineering that ability has been a challenge for robotics researchers. Some soft robots that store energy can perform a single impressive jump very infrequently. Some lightweight soft robots that don’t store energy can jump frequently but can’t jump high or far enough to successfully cross an obstacle.

For inspiration, the researchers looked to gall midge larvae (瘿蚊幼虫) that miraculously throw themselves across distances 30 times as long as their loglike bodies. A gall midge larva bends its body and squeezes the liquid in its body to one end, making it rigid (僵硬的). The accumulation of liquid builds up pressure, and releasing the pressure sends it soaring (飙升). The robot’s body doesn’t resemble (像) that of a gall midge larva, but it jumps like one. Its body is made of two small plastic bags printed with electrodes; the front bag is filled with liquid and the back one is filled with the same volume of air. The robot uses electricity to drive the flow of liquid, which causes the body to bend and generate force with the ground, resulting in a jump. And the air bag imitates the function of an animal’s tail, helping the robot keep a stable position.

While the robot is currently restricted to Earth, it might be right at home exploring another planet. If this is true, the researchers robot might jump over dusty rocks and large holes on the moon or Mars, going where no pancake has gone before.

1．What does the author want to show by mentioning a pancake?

A．A pancake’s dream to have legs is unrealistic.

B．A robot is capable of serving a good pancake.

C．A pancake-shaped robot can jump without legs.

D．Research on pancakes advances our understanding of robots.

2．What difficultly do robotics researchers have in developing Hop according to Paragraph 2?

A．Hop’s avoiding an obstacle.	B．Hop’s moving around by rolling.
C．Hop’s performing one remarkable jump.	D．Hop’s jumping high and far continuously.

3．What inspiration do the researchers draw from gall midge larvae?

A．They are shaped like logs.

B．They have tails to change positions.

C．They bend their bodies and increase force.

D．They are filled with liquid and have rigid bodies.

4．What is the author’s attitude to the future of the new robot?

A．Intolerant.

B．Positive.

C．Indifferent.

D．Ambiguous.