In the questions below, the passage consist of six sentences. The first and the sixth sentences are given. (S1, S6) The middle four sentences in each have been removed and jumbled up. These are labeled as P, Q, R and S. Find out the proper order for the four sentences.
S1: Metals are today being replaced by polymers in many applications.
P: Above all, they are cheaper and easier to process making them a viable alternative to metals.
Q: Polymers are essentially a long chains of hydrocarbons molecules.
R: Today polymers as strong as metals have been developed.
S: These have replaced the traditional chromium - plated metallic bumpers in cars.
S6: Many Indian Institutes of Science and Technology run special programmes on polymer science.
The proper sequence should be: