With technologies first researched and developed for space     1    , we can solve some of the big problems facing mankind, making our lives safer and easier. One of these is earthquake shock absorbers. Shock absorbers     2     applied to the space shuttle launch have also been set up in the cities with a high     3     of earthquakes in order to protect buildings and save lives. Some technologies need     4     research to better solve real-life problems. For example, liquid hydrogen is a clean     5     energy source that is used widely as rocket fuel, and it is     6     that hydrogen fuel cell vehicles will be mass-produced and     7     in the near future. These scientific and technological     8     can provide benefits to societies on the Earth in many areas     9     health, energy and information technology. This should be a strong     10     for continuing to explore space.

No matter how exciting space exploration sounds, there’s an important point that needs to be considered: food supplies. Right now, astronauts typically       1     (依赖) dry food in airtight bags and cans, since there are strict weight limits on items taken into space. Foods that we     2     (认为是理所当然的), such as fresh fruit and vegetables, are out of the question for space explorers.

For those who     3     (有强烈的愿望) to grow food during space flights, they’ve faced many difficulties, including the absence of gravity, and a lack of soil, air and humidity (湿度). However, growing food to add and minimize the food that must be carried to space will be increasingly important on long-duration flights into space. Recently, a leading team has worked out how plants can absorb nutrients from human urine (尿). Human urine is 95 percent water, with the other 5 percent    4     (构成；组成) nutrients which are harmful to the human body but not to plants, and it could supply three to four out of the six nutrients that plants need. By recycling liquid waste and producing food, an efficient cycle will be created.

And most importantly, the duration of space flights will be greatly extended to “20 years of flight”, meaning we may be soon sending astronauts on flights to Mars, or even beyond.