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. Earth is the third planet from the Sun and the only astronomical object known to harbour life. 
P. About 29% of Earth's surface is land consisting of continents and islands.
Q. It is mostly covered by oceans but lakes, rivers and another freshwater also constitute the hydrosphere. 
R. The remaining 71% is covered with water.
S. Much of Earth's polar regions are covered in ice. 
6. Earth's outer layer is divided into several rigid tectonic plates that migrate across the surface over many millions of years.