Read carefully the passage given below and answer the questions that follow:All acquisitions are fruitful in their proper form. So is the case with learning and knowledge. Learning is a long and open-minded pursuit. Only those who have humility have real learning and knowledge. This humility comes from their enlightened realization and learning and knowledge are too vast for any individual to grasp them all. The higher one goes on the mountain of knowledge more and more peaks come to one's sight. Finally he has to realise that he is too limited to have access to them all. But a person having only a little learning thinks that he has known everything. He has not gone to the height of knowledge so he cannot know the peaks. He is like an empty vessel that sounds much but has nothing inside it. Thus a little learning is a very dangerous thing. Questions : (a) What is learning? (b) Who is like an empty vessel? (c) Who has real learning and knowledge? (d) Who knows that he has known everything?