听力原文: Some students at the Open University left school 20 years ago. Others are younge
The first name for the Open University was The University of the Air. The idea was to teach on the air, in other words, on radio and television. Most of the teaching is done like this. Radio and television have brought the classroom into people's homes. But this, on its own, is not enough for a university education. The Open University student also receives advice at one of 283 study centers in the country; 36 weeks of the year, he has to send written work to a tutor, the person who guides him. He must also spend three weeks every summer as a full-time Student. Tutors and students meet and study together, as in other universities. At the end of the Open University's first year, the results were good. Three out of every four students passed their examinations. If they do this every year, they will finish their studies in four or five years.
(27)
A.Because it isn't closed.
B.Because the students have to pass all examinations before entering it.
C.Because there is no examination before they are accepted as students.
D.Because its door is open.