The following sentences form a paragraph. The last sentence of the paragraph is given. The rest of the sentences are numbered as P, Q, R, S and T. These parts are not given in their proper order. Read the sentences and choose the alternative that arranges them in correct order.

P. Konstantin Tsiolkovsky first described a space elevator in 1895.

Q. While elevator travel wouldn't be faster than rocket travel, it would be much less expensive and could be used continuously to transport cargo and possibly passengers.

R. A space elevator is a proposed transportation system connecting the Earth's surface to space.

S. Tsiolkovksy proposed building a tower from the surface up to geostationary orbit, essentially making an incredibly tall building.

T. The elevator would allow vehicles to travel to orbit or space without the use of rockets.

The problem with his idea was that the structure would be crushed by all the weight above it.