A、The number of students they take in is limited. B、They receive little or no support from public taxes. C、They are only open to

[19]Religious and private schools receive little or no support from public taxes in the United States. As a result, they are more expensive to attend. [21]The religious schools in America are usually run by churches. Therefore they tend to be less expensive than private schools. When there is free education available to all children in the United States, why do people spend money on private schools? Americans offer a great variety of reasons for doing so. Some parents send their children to private schools because the classes there are usually smaller. [20]In their opinion, the public schools in their area are not of high enough quality to meet their needs. Private schools in the United States range widely in size and quality, and they offer all kinds of programs to meet the needs of certain students.
19. Why is it usually expensive to attend religious and private schools?
20. What is one of the reasons for people to send their children to private schools?
21. Who usually runs religious schools in the United States?