Directions (For the following 21 items) :

In this section there are six short passages. Each passage is followed by items based on the passage. Read each passage and answer the items that follow.

What were the early ideas of men about the sky and the earth? They naturally believed that the earth was motionless, and they also supposed that it was flat. These two ideas do not surprise us. Children now-a-days think the same until they are taught differently. How were men to know that the earth was a ball circling round the sun? They had no telescope for accurate observation. They had not travelled round the world. In fact, many parts of the world in those days were unexplored and unknown. They thought they lived on a kind of flat plate, and that the sky with the sun and the moon and the stars, was a kind of inverted bowl turning round above them. The sun, the moon and the stars were their lamps for day and night.

What was the main cause of the early man's wrong ideas?