16. Mom bought me ______ MP3 for my birthday present last Sunday.
A. the B. an C. a D. 不填
17. ---How long have you _______?
---5 years.
A. married B. got married C. married D. been married
18. The singer became famous in the early 1980s, ______ the classical music was better than pop music.
A. which B. when C. that D. where