A、They award their own degrees. B、They select their own students. C、They set their own exams. D、They organize their own laborato

"Where is the university?" is a question many visitors to Cambridge ask. But no one could point them in any one direction because there is no campus. The university consists of 31 self-governing colleges. It has lecture halls, libraries, laboratories, museums and offices throughout the city.
    Individual colleges choose their own students who have to meet their minimum entrance requirements set by the university. Undergraduates usually live and study in their colleges, where they are taught in very small groups. Lectures, laboratories and practical work are organized by the university and held in university buildings.
    There are over 10,000 undergraduates and 3,500 postgraduates. About 40% of them are women and some 8% from overseas. As well as teaching, research is of major importance. Since the beginning of the 20th century more than sixty university members have won Nobel prizes.
    The university has a large number of buildings for teaching and research. It has more than 60 specialist subject libraries, as well as the university library, which as the copyright libraries, is entitled to a copy of every book published in Britain.
    Examinations are held and degrees are awarded by the university. It allowed women to take the university exams in the 1881, but it was not until 1948 that they were awarded degrees.
Questions 20 to 22 are based on the passage you have just heard.
20. Why is it difficult for a visitor to locate Cambridge University?
21. What can we learn about the colleges of Cambridge University?
22. What does the passage tell us about women students in Cambridge University?