Directions: In the question given below, the first and sixth sentence are given in the beginning as S1 and S6. The middle four sentences have been 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 it as your answer.

S₁ : What soda-water is composed of you may see for yourself if you watch your glass as it stands on the table after you have slaked your first thirst. S₆ : 'Carbonic acid' is the old name for it, but it is more correct to name it, when it is out of the water, 'Carbon dioxide'. P : The liquid is plain water, as you will find out if you are too slow about drinking. Q : You will see that it is separating into two different things, a liquid and a gas. R : The gas is so heavy that you can fairly drink it from the glass, and it has, as you know, a tingle-tangle taste. S : The other is a heavy, sour and invisible gas that slips up through the water in little bubbles and collects in the empty half of the glass.