Once ______ , the plan can’t be changed.
19. The language used in advertisements differs from____________used in ordinary readings.
18._________is often the case, he didn’t study hard and failed to pass the test.
16.You can't imagine that a well-behaved gentleman__________be so rude to a lady.
15.--How about eight o'clock outside the cinema? --That________me fine.
14. With some books badly needed_________, she hurried to the bookstore.