Every day 25 million US children ride school buses. The safety record for these buses is much better than for passenger cars; but nevertheless, about 10 children are killed each year riding on large school buses, and nearly four times that number are killed outside buses in the loading zones. By and large, however, the nations school children are transported to and from school safely. Even though the number of school bus casualties(伤亡事故)is not large, the safety of children is always of intense public concern. While everyone wants to see children transported safely, people are divided about what needs to be done — particularly whether seat belts should be mandatory(强制性的). Proponents of seat belts on school buses — many of them are parents and medical organisations — argue that seat belts are necessary not only to reduce fatality and injury, but also to teach children lessons about the importance of using them routinely in any moving vehicle. A side benefit, proponents point out, is that seat belts help keep children in their seats, away from the bus driver. Opponents of seat belt installation suggest that children are already well protected by the school buses that adhere to the National Highway Traffic Safety Administrations(NHTSA)safety requirements set in 1977. They also believe that many children wont wear seat belts anyway, and that they may damage the belts or use them as weapons to hurt other children. A new Research Council report on school bus safety suggests that there are alternate safety devices and procedures that may be more effective and less expensive. For example, the study committee suggested that raising seat backs four inches may have the same safety effectiveness as seat belts. The report sponsored by the Department of Transportation at the request of Congress, reviews seat belts extensively while taking a broader look at safety in and around school buses. What information can we get from the first paragraph?