Which reason for students’ absences is discussed in great detail? [originaltext]

In some large American city schools, as many as 20%-40% of the students are absent each day. There are two major reasons for such absences: one is sickness, and the other is truancy. That is staying away from school without permission. (18)Since school officials can’t do much about the illness, they are concentrating on reducing the number of truancies. One of the most promising schemes has been tried in Florida. (19)The pupils there with good attendance have been given free hamburgers, toys and T-shirts. Classes are told if they show improved rates of attendance, they can win additional gifts. At the same time, teachers are encouraged to inspire their students to come to school regularly. When those teachers are successful, they are also rewarded. "We’ve been punishing truancy for years, but that hasn’t brought them back to school, " one school principal said. Now we are trying the positive approach. Not only do you learn by showing up every day, but you earn. In San Francisco, the board of education has had a somewhat similar idea. (20) Schools that show a decrease in deliberate destruction of property can receive the amount of money that would be spent on repairs and replacements. For example, 12, 000 dollars had been set aside for a school’s property damages every year. Since repair expenses of damaged property required only 4, 000 dollars, the remaining 8, 000 dollars was turned over to the student activity fund. "Our democracy operates on hope and encouragement, " said the school board member. "Why not provide some positive goals for students and teachers to aim at?"