Directions: In the following items, each passage consists of six sentences. The first sentence (S1) and the final sentence (S6) are given in the beginning. The middle four in each have been removed and jumbled up. These are labeled P, Q, R and S. You are required to find out the proper sequence of the four sentences and mark accordingly on the answer sheet.
S1 : The earth was initially very hot and without an atmosphere. S6 : But it contained a lot of other gases that are poisonous to us. P : The atmosphere came from the emission of gases from the rocks. Q : Because it contained no oxygen. R : In the course of time it cooled and acquired an atmosphere. S : This early atmosphere was not one in which we could have survived. The proper sequence should be