No beast on Earth is tougher than the tiny tardigrade (缓步类动物). It can【C1】_____being frozen at -272° Celsius, being exposed to the vacuum of outer space and even being【C2】__with 500 times the dose of X-rays that would kill a human. In other words, the creature can endure conditions that don’t even exist on Earth. And researchers are looking to the microscopic animals to learn how to prepare humans and crops to handle the【C3】_____of space travel.

The tardigrade’s indestructibility stems from its【C4】_____to its environment—which may seem surprising, since it lives in【C5】_____comfortable places, like the cool, wet patches of moss (青苔) that dot a garden wall.

But it turns out that a tardigrade’s damp, mossy home can dry out many times each year. Drying is pretty【C6】_____for most living things. It does damage to cells in some of the same ways that freezing, vacuum and radiation do. Tardigrades, however, have【C7】_____special strategies for dealing with these kinds of damage.

As a tardigrade dries out, its cells produce several strange proteins that are unlike anything found in other animals. In water, the proteins are shapeless. But as water disappears, the proteins self-assemble into long fibers that fill the cell’s【C8】_____. The fibers support the cell’s membranes (细胞膜) and proteins, preventing them from breaking or【C9】_____.

Emulating tardigrades could one day help humans colonize outer space. Food crops could be engineered to produce tardigrade proteins, allowing these organisms to grow more efficiently on spacecraft where levels of radiation are elevated compared with on Earth.

So if humans ever succeed in reaching the stars, they may accomplish this【C10】________, in part, by standing on the shoulders of the tiny eight-legged endurance specialists in your backyard.

A) adaptations E) feat I) rigors M) thrill

B) blasted F) interior J) seemingly N) unanimously

C) catastrophic G) probing K) survive O) unfolding

D) evolved H) recurrence L) tempt

【C6】