55.What is the purpose of publishing Twain's autobiography?
A、To supplement other biographies.
B、To help readers to understand Mark Twain.
C、To introduce Mark Twain's works.
D、To expose new discoveries about Mark Twain.
20.In October 2007,the Chang'e-l satellite was successfully __at Xichang.
A、launched
B、presented
C、regulated
D、engaged
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.