Questions 13 to 15 are based on the passage you have just heard.
13
A.He uses the Internet to teach mathematics.
B.He uses rap videos to teach mathematics.
C.He plays films performed by his students.
D.He plays mathematics games with his students.
14
A.They can't adapt themselves to the new environment.
B.Most of them are poor in mathematics.
C.They drop out due to language obstacles.
D.They are mostly overseas students.
15
A.He desires to be an outstanding educator.
B.He wants mathematics to be the subject students like learning.
C.He hopes to help students to be admitted into universities.
D.He wishes to be helpful for graduates to get a job.