WHY BUILD A SPACE ELEVATOR? The space elevator will reduce the cost of getting from Earth to space. It will also allow us to take very large payloads into space very easily, very safely. Because of that, we can build cities on the moon. We can build space stations. We can build large solar arrays in space to collect energy from the sun and beam it down to Earth. WHY NOT JUST USE ROCKETS INSTEAD? Rockets are very expensive. The shuttle costs $10,000 a pound to put a payload into low-Earth orbit, and if you want to go to the moon or Mars, it.s hundreds of thousands of dollars per pound or more. Rockets are also very limited in the amount of payload they can carry, and they.re risky. With a space elevator, the cost is a fraction of that—it may go down to 100th or 1,000th of current costs—and there are no rocket engines that might explode. WHAT WOULD IT BE LIKE TO RIDE THE ELEVATOR? You.d go to an ocean platform, you.d climb into a module, and you.d feel it start moving. You.d see the Earth fall away. In just a half hour or so, you.d pass up through the clouds, and you.d start to see the curve of the horizon. Another half an hour to an hour later, you.d basically be in space. You.d see stars, even in the middle of the day. Eventually you.d be weightless. It.d be a very smooth ride; there wouldn.t be any shaking. ARE THERE POTENTIAL DRAWBACKS TO OPENING SPACE THIS WAY? Everything we do has the potential for creating some bad. If we mine an asteroid, the asteroid.s going to look ugly, just like a mine here. But I think the benefits of opening up space far outweigh the damage that we can see—benefits in terms of gaining energy from space to replace oil, additional capabilities in telecommunications, manufacturing in space, additional real estate and exploration.

1-1、If a space elevator is built, what can’t be built by us?
A、Cities on the moon.
B、Space stations.
C、Skyscrapers in space.
D、Expressways in space.

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