355. The high speed rail system in China has experienced _____ growth which no other infrastructure programs in the world have ever seen so far.
(A) adequate
(B) prototypical
(C) unprecedented
(D) prolonged
572. The president’s popularity has _______ since the election. It is doubtful if he will still win the presidency for the second term.
(A) undone
(B) declined
(C) tracked
(D) shrunk
762. Compared with adults, infants are more ______ to melamine-contaminated milk powder and develop kidney stones.
(A) brave
(B) embarrassed
(C) scared
(D) vulnerable