1. (2021九下·温州竞赛) 阅读理解

American researchers from Washington University say they have invented a method that could produce oxygen and fuel with salty water on Mars. It would support future human exploration activities on Mars.

The method operates with electrolysis. The machine the researchers created is called an electrolyzer. The researchers say it can separate salty water into oxygen and hydrogen gases. Oxygen would be needed for humans to breathe, and hydrogen could be used to fuel spaceships and machines.

The method is practical because scientists have already found that Mars once had huge amounts of water, and that the planet probably has much water today. But most of the water is thought to exist in the form of ice because of the cold weather. So the research team notes that any water that is not frozen is almost surely full of salt.

The new method is cheap and environment-friendly. It can take salty water directly and change it into oxygen and hydrogen. However, the usual process can be difficult, costly and harmful to the environment. It requires the salt to be removed first.

Compared with the method used by NASA (the.US space agency), the new method is more effective. The NASA machine is designed to change carbon dioxide(CO₂) from Mars into oxygen, which has been tested on Mars. The lead researcher on the new method said the new method could produce 25 time more oxygen than the NASA method, while using the same amount of power. It can also produce hydrogen fuel, which the NASA method cannot. However, the new method hasn't been experimented on Mars yet.

In a news release, the engineering team also suggested the new method could even find valuable uses on the earth. It could possibly be used to change salt water into oxygen and hydrogen through "seawater electrolysis". It may also be able to provide oxygen to researchers exploring new environments in the deep sea.

1. （1） The researchers use ____________ to separate salty water on Mars.

   A . fuel B . electrolyzer C . oxygen D . hydrogen
3. （2） What advantage does the new method have?

   A . It improves the sea environment on the earth. B . It can change fresh water into oxygen and fuel. ' C . It produces less carbon dioxide than the NASA method. D . It saves much money for no need to remove salt from water.
5. （3） From the passage, we learn that ____________.

   A . the ice on Mars makes it difficult to use the new method B . scientists have already carried out the new method on Mars C . the new method needs salty water that is easy to find on Mars D . a large amount of CO₂can be produced with the NASA method
7. （4） What's the best title of the passage?

   A . A Step Forward on Mars B . How to Live on Mars C . A New Method from NASA D . Ways of Water Electrolysis