Directions: The following passage consists of six sentences. The first sentence (S₁) and the final sentence (S₆) are given in the beginning. The middle four sentences have been removed and jumbled up. These are labelled as P, Q, R and S. You are required to find out the proper sequence of the four sentences and mark your answer accordingly. S₁ : The ancestors of whales, it is said, lived on land, for they still have slight traces of hind-legs. S₆ : It has flippers on its sides to keep it balanced and layers of fat or oil under the skin which furnish heat and make the huge body light and buoyant. P : But ages ago, whales changed their home-moving from the land to the sea. Q : It is shaped like a submarine boat, with a tail turned into a power paddle. R : The whale is suited to live in water. S : They are warm-blooded animals and feed their babies as land mammals do.