In this section, each item consists of six sentences of a passage. The first and sixth sentences are given as SI and S6. The middle four sentences in each have been jumbled up and labelled as P, Q, R, and S. You are required to find the proper sequence of the four sentences and mark your response accordingly.

S1: The wool comes from sheep, goats, yak, and some other animals.

P: These wool-yielding animals bear hair on their body.

Q: So, hair keeps these animals warm. 

R: Hair trap a lot of air.

S:  Air is a poor conductor of heat. 

S6: Wool is derived from these hairy fibres.