Directions:In each of the following groups of words,there are four underlined letters or letter combinations marked A,B,C and D.Compare the underlined parts and iden-tdtify the one that is different from the others in pronunciation.Mark your answer by blackening the corresponding letter on the Answer Sheet.
A、combination
B、climbing
C、bamboo
D、ambition
(23)__
A、for example
B、in addition
C、at last
D、after all
49.Which event brought the booming of American candy bar business?