S₁: The heart is pump of life.
P : They have even succeeded in heart transplants.
Q : Nowadays surgeons are able to stop a patients heart and carry out complicated operations.
R : A few years ago it was impossible to operate on a patient whose heart was not working properly.
S : If heart stops we die in about five minutes.
S₆: All this was made possible by the invention of heart-lung machine.

The Proper sequence should be:

S₁: A force of exists between everybody in the universe.
P : Normally it is very small but when the one of the bodies is a planet, like earth, the force is considerable.
Q : It has been investigated by many scientists including Galileo and Newton.
R : Everything on or near the surface of the earth is attracted by the mass of earth.
S : This gravitational force depends on the mass of the bodies involved.
S₆: The greater the mass, the greater is the earth's force of attraction on it. We can call this force of attraction gravity.

The Proper sequence should be:

S₁: Calcutta unlike other cities kepts its trams.
P : As a result there horrendous congestion.
Q : It was going to be the first in South Asia.
R : They run down the centre of the road.
S : To ease in the city decided to build an underground railway line.
S₆: The foundation stone was laid in 1972.

The Proper sequence should be:

S₁: For some time in his youth Abraham Lincoln was manager for a shop.
P : Then a chance Customer would come.
Q : Young Lincoln way of keeping shop was entirely unlike anyone else's.
R : Lincoln would jump up and attend to his needs and then revert to his reading.
S : He used to lie full length on the counter of the shop eagerly reading a book.
S₆: Never before had Lincoln had so much time for reading as had then.

The Proper sequence should be:

S₁: All the land was covered by the ocean.
P : The leading god fought the monster, killed it and chopped its body in to two halves.
Q : A terrible monster prevented the gods from separating the land from the water.
R : The god made the sky out of the upper part of the body and ornamented it with stars.
S : The god created the earth from the lower part, grew plants on it and populated it with animals.
S₆: The god moulded the first people out of clay according to his own image and mind.

The Proper sequence should be: