I . Phonetics( 5 points)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 identify the one that is different from the others in pronunciation. Mark your answer by blackening the corresponding letter on the Answer Sheet.1.( )
A、cake
B、gas
C、bag
D、tax
7. By the time he retires, Carl _____ president for 15 years at the university.
A、would be
B、will have been
C、will be
D、 has been
12. There are enough nigh schools in this city. Adults can be educated no matter _____old they are.