Directions: In the question, the first and the last sentences/parts of the passage/sentences are numbered 1 and 6. The rest of the passage/sentences are split into 4 parts and labelled P, Q, R and S. These four parts are not given in a proper order. Read the passage or sentence and find out which of the 4 combinations is correct.

1. The houses in the Indus Valley were built of baked bricks. P. This staircase sometimes continued upwards on to the roof. Q. Access to the upstairs rooms was by a narrow stone staircase at the back of the house. R. The drains were incorporated in the walls. S. The houses had bathrooms and excellent drainage systems.
2. They led outside into covered sewers which ran down the side of the streets.