Complete the text with these prepositions: “about, at, for, in, of, to, with”. You will have to use some prepositions more than once. (Hoàn thành văn bản với các giới từ sau: “about, at, for, in, of, to, with”. Bạn sẽ phải sử dụng một số giới từ nhiều hơn một lần.)

If somebody told you they were building a lift to take people into space, you would probably laugh (1) the idea. But in fact, if you listen (2) scientists and engineers talking about the plan, you soon realise they are being completely serious.

The elevator would consist (3) a carbon fibre ribbon 100,000 km long. One end would be in the ocean at the equator, and the other end would be in space.

At the moment, it takes months or years to prepare (4) have begun searching (5), a trip into space by rocket. Space agencies a better option - partly because they worry (6) the cost of space missions. The idea of a space elevator appeals (7) governments because it would be far cheaper than sending rockets into space. It would be slower, but that would give passengers more time to adjust (8) the different conditions as they left the earth.

It may not be easy though: countries might argue (9) the political leaders can cope (10) these problems and manage to take part (11) the project together, it is certainly possible.

Science fiction writer Arthur C, Clarke wrote a novel (12) the idea in 1979. He said in a speech that humans would build a space elevator ten years after they stopped laughing at the idea. Well, they've stopped laughing now.