Direction: In the following question, the 1st and the last part of the sentence/passage are numbered 1 and 6. The rest of the sentence/passage is split into four parts and named P, Q, R and S. These four parts are not given in their proper order. Read the sentence/passage and find out which of the four combinations is correct.

1. There are many planetary systems like ours in the universe, with planets orbiting a host star.
P. Our planetary system is named the "solar" system.
Q. Our planetary system is located in an outer spiral arm of the Milky Way galaxy.
R. Because our Sun is named Sol, after the Latin word for Sun, "solis," and anything related to the Sun we call "solar." 
S. Beyond our own solar system, we have discovered thousands of planetary systems orbiting other stars in the Milky Way. 
6. Scientists are trying day and night to find new planetary systems.