寻找适合在火星上种植的蔬菜
Scientists are trying to get humans to Mars. Researchers from the U.S. space agency NASA are currently trying to find out what kind of plants could grow in the red soil on Mars. They hope that astronauts will be able to start growing their own food on the red planet. The journey to Mars could take up to two-and-a-half years. The astronauts will need to take a lot of food with them just to last for the journey. They will never be able to return to Earth, which means they will need to grow their own fruit, vegetables and other plants from seeds. NASA said there could be a problem because Mars doesn’t have arable land that is suit for growing things. It just has red dust.
Humans may be on their way to Mars fifteen years later. NASA has been testing special “Martian gardens” to see what kind of things might grow on Mars. They have used a special soil made up of crushed volcanic rock(碎火山岩). It contains no nutrients or organic material, so it is similar to the soil on Mars. The scientists managed to grow lettuce in it. They said the lettuce tasted normal, but it had weaker roots and took longer to grow. They will now try growing other vegetables. A NASA spokesman said, “Discoveries made in these Earth-based ‘Martian gardens’ will prepare well for future studies and technology development in terms of reliable, efficient food production a long way from Earth.”
1.Why do people hope to grow food on Mars?
A To make astronauts there eat well.
B To continue astronauts’ journey.
C To help astronauts return to Earth.
D To grow something in the red soil.
解析：选B。B 细节理解题。根据第一段“The astronauts will need to take a lot of food with them just to last for the journey. They will never be able to return to Earth...”可知登陆火星的宇航员将永远无法回到地球，他们需要携带大量食物才能继续他们的旅程，说明这些宇航员在火星上需要自给自足，故 选 B。
2.What does the underlined word “arable” probably mean?
A 可耕种的.
B 可聚集的.
C 可养殖的.
D 可繁殖的.
解析：选A。A 词义猜测题。根据第一段“Mars doesn’t have arable land that is suit for growing things.” 可 知arable land 指的是适合种植东西的地，即“可耕种的”，故选 A。
3.When might people be on Mars according to the passage?
A Before 2037.
B In 2037.
C In 2040.
D In the next 15 years.
解析：选C。C 推理判断题。根据第一段“The journey to Mars could take up to two-and-a-half years.”和第二段“Humans may be on their way to Mars fifteen years later.”可知去火星需要 2.5 年时间，文章预测 15 年(2022+15=2037 年)以后人类会在去往火星的路上，即应该是在 2037 年以后人类才可能在火星上，故选 C。
4.How was the lettuce grown in the “Martian gardens”?
A It was similar to the soil on Mars.
B It needed little time to grow.
C The roots were stronger.
D It had a usual taste.
解析：选D。D 细节理解题。根据第二段“They said the lettuce tasted normal, but it had weaker roots and took longer to grow.”可知这些莴苣吃起来味道很正常，但是它的根茎较弱，生长时间较长，故选 D。
5.The passage may be from _________.
A a science magazine
B a health magazine
C a traveling magazine
D a sports magazine
解析：选A。A 文章出处题。本文围绕寻找适合在火星上种植的蔬菜展开，属于科学研究，故选 A。