Reading comprehension (阅读理解)Some scientists believe that Mars is the planet with the highest chance of supporting human life apart from the Earth. Of these scientists, some believe that it is possible for humans to reach Mars by 2030. However, there are many questions to answer and things to prepare before this can happen. Scientists must research Mars as well as develop the technology for a person to live safely there. Putting people on Mars will include planning how a person will live on Mars. At its shortest distance, Mars is 225 million kilometers away from the Earth. So, it would take about months for a one-way trip to get there. The planets are moving around the sun at different rates, though. So, astronauts would have to remain on Mars for over 18 months before the Earth and Mars are at their closest distance again. Therefore, planning for such a long trip to Mars would include figuring out how much food and supplies would be needed for over two years in space and how such things would be cared. Astronauts would need to prepare both their minds and bodies for such a long trip away from the Earth. NASA set up a special research building in Hawaii that copied the living conditions on Mars. A group of astronauts stayed in this research building for 366days. During their stay, they had to deal with what they might have to deal with on Mars.For example, they had to eat bad food. They had to live with each other in a very small space. They also had to deal with the problem of having lots of time with little or nothing to do. They could not receive help from people on the outside for the whole time they were inside. But it is all part of the plan for preparing to put people on Mars one day. 2. How long would people have to stay on Mars?