What would it be like to live on Mars? Volunteers are spending eight months in an area that looks much like the surface of Mars. They are isolated（孤立）high on top of Mauna Loa, a volcanic mountain on the Big Island of Hawaii, living on a simulated（模仿的）or make-believe, Mars Base.
The project called HI-SEAS is in the charge of Kim Binsted. She says this wild environment is as close to Mars as you can find on Earth. Because it is so high, the land is not warm or rich with plants, like the rest of Hawaii.
"You will see there is really no visible plant life or animal life. And you have got this wonderful volcanic material."
Mauna Loa,2,500 meters above sea level, is geologically very similar to Olympus Mons on Mars and almost as tall as that Martian mountain. When measured from its base, deep in the ocean, Mauna Loa is the second largest mountain in our solar system, after the one on Mars.
The six member HI-SEAS crew is mostly self-sufficient. Food and supplies are brought to them. But the individuals bringing those supplies cannot communicate with volunteers inside the habitat or base.
Kim Binsted says this experiment looks at how the astronauts get along with each other."We study how well they work together, how we can keep them happy and supported, and not wanting to kill each other over these long durations（期间）."
Crew members communicate with the outside world through e-mail and blogs. They also produce video on the YouTube website, like this one from mission commander Martha Lenio.
"I am really enjoying this opportunity to live here and pretend that I'm on Mars and get to learn all sorts of new skills." One of them said.
Whoever gets there first, the trip will not be easy, says Kim Binsted.
"It is going to be challenging."
21.What do we know about Olympus Mons?
A. It is 2,500 meters above sea level. B. It is geologically similar to Mauna Loa.
C. It is the second largest mountain on the earth. D. It is a mountain on the Big Island of Hawaii.
22What is the purpose of the experiment?
A. To set up a space station.
B. To explore new settlement for human.
C. To study how the astronauts treat each other.
D. To prove human can live in whatever conditions.
23.Which can be the best title for the next?
A. Volunteers First Explore Mars B. Volunteers Experience Life in Hawaii
C. Volunteers Get Taste of Mars in Hawaii D. Volunteers Study the Environment on Mars