A．Twelve'-grade students．
B．Students whose fathers are farmers．
C．Students of agriculture majors.
D．Students who are good at math or science．
A．From his father.
B．From AT&T.
C．From his university．
D．From CNN report．Passage Three
A．Niche phone cards.
B．International phone cards.
C．Domestic phone cards.
D．Prepaid phone cards．