Some scientists say there will not be enough land for Earth in the near future. So some other places should    1     (find) to live. While some scientists are considering     2     (build) communities on the Moon and Mars, other scientists feel independent space stations could bring many more     3     (benefit).

So what is wrong    4     the Moon or Mars? Firstly, the distances are a problem. The Moon is about 384,400 miles from Earth. Mars is over 55 million miles away. The journey to the Moon takes about eight days, and the one to Mars takes from six to eight months. It will be both time-consuming and    5     (danger) to get settlers to these distant places. Moreover, it takes a message up to 44 minutes to go from Earth to Mars,     6     makes fast communication impossible. However,     7     space station circling Earth is just a few hours away. This makes the trip much cheaper and communication    8     (relative) easy. Furthermore, the    9     (absent) of light at night on the Moon and Mars isn’t a good thing either. On a space station, however, the sun’s energy can be made available     10     (support) people living there 24 hours a day.