[b] in debate and [i] in delate can be said to form a(n) ______.
A. phonemic contrast
B. complementary distribution
C. assimilation rule
D. sequential rule
Unlike watching TV, reading is a highly active process(过程) () it requires attention as well as memory and imagination.
A. until
B. but
C. unless
D. for
() send your motorcycle to be repaired You'd better not drive it any more.
A. Wily
B. Why not
C. Why don't
D. Why didn't
He () be in the classroom because he was seen playing football on the play- ground.
A. mustn't
B. can't
C. may not
D. isn't able to