30. B
31. D
32. B
33. B
34. B
Giải:
30. Every year students in many countries learn English. Some of these students are young children. Others are teenagers. Many are adults.
31. Most people must work hard on their lessons to learn another language.
32. Many boys and girls learn English at school because it is one of their subjects.
33. In England, America or Australia, many boys and girls study their own language, which is English, mathematics and another language, perhaps French, German or Spanish.
34. Many adults learn English because it is useful for their work