A、Courses in British history. B、Language courses. C、Courses in sports. D、Teacher training courses. B短文中提到，夏令营的学生不仅在课堂上说英语(speak

Most summer school courses in Britain last for two to four weeks. During that time, students live either with a British family, or at the school, or in a hotel. They have about 15 hours of lessons every Monday to Friday usually in the mornings. Each school has a lot of different courses. Some are for beginners and others are for intermediate or advanced students. The lessons are fun; the classes are small and the teachers are all from English-speaking countries. But summer school students don’t just speak English in the classroom. They are in Britain, so they speak and read and hear it outside too. That’s why they learn so quickly and why a summer school course is really a holiday. Only one third of each course is taught in the classroom. The rest takes place during a busy afternoon and evening timetable of visits, sports and games. These activities help everyone to make new friends, have fun and improve their English.
19. What kind of course do summer schools offer?
20. Why do summer schools arrange visits and other activities for the students?
21. Why do students in summer schools learn quickly?