3.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.
A、useless
B、endless
C、unless
D、hopeless
Your brother Frank doesn't eat cheese, ____?
A、is he
B、isn't he
C、does he
D、doesn't he
Tom is a careless person. He forgot ____ the door again when he went out yesterday.