There once was an old man aged 50,who had a lazy son aged 30. The son couldn't earn his own living , and still lived on his old father for food and clothing. The old man was very worried about him. So he took him to the fortune teller to have his fortune told.The father and son both believed what the fortune teller said --the father would live to 80 and the son to 62. After they found out how long they were going to live, the son was very sad. His father comforted him, "Don't be so sad! You are only 30 now, and still have 32 years of good days _ you." "I'm not worrying about my own age. It's your age which causes me great worry," the son said. The father was greatly moved and said, "Don't worry about me so much. I've got 30 years _ me too." "I'm not worried about your age either," said the son. "I have found out that you will die two years earlier than I. So who will I depend on in the two years after your death?" The son was worried about his father because  _  .
he liked his father very much he would have no money to buy food and clothing if his father died his father was getting older and older His father would get less and less money