A、They may take a long time to solve. B、They need assistance from the city. C、They have to be dealt with one by one. D、They are

(19) Mark felt that it was time for him to take part in his community, so he went to the neighborhood meeting after work. (20) The area’s city councilwoman was leading a discussion about how the quality of life was on the decline. The neighborhood faced many problems. Mark looked at the charts taped to the walls. There were charts for parking problems, crime, and for problems in vacant buildings. Mark read from the charts: police patrols cut back, illegal parking up 20% . People were supposed to suggest solutions to the councilwoman. It was too much for Mark. (21) "The problems are too big," he thought. He turned to the man next to him and said, "I think this is a waste of my time. Nothing I could do would make a difference here. " As he neared the bus stop on his way home, Mark saw a woman carrying a grocery bag and a baby. As Mark got closer, her other child, a little boy, suddenly darted into the street. The woman tried to reach for him, but as she moved, her bag shifted and the groceries started to fall out. Mark ran to take the boy’s arm and led him back to his mother. "You gotta stay with Mom" , he said. Then he picked up the street groceries while the woman smiled in relief. "Thanks!" she said. "You’ve got great timing!" "Just being neighborly," Mark said. As he rode home, he glanced at the poster near his seat in the bus. " Small acts of kindness add up. " (22) Mark smiled and thought, "Maybe that’s a good place to start. "
19. What did Mark think he should start doing?
20. What was being discussed when Mark arrived at the neighborhood meeting?
21. What did Mark think of the community’s problems?
22. Why did Mark smile on his ride home?