_______ we couldn’t understand was _______ more and more students went abroad after graduation.
17. I didn’t get into the two-hour quarrel; I know how it ______, though.
16.It is no doubt that once ____ this city, you’ll find that there is so much surprise waiting for you to discover. visit B. visiting C. visited D. to visit
15. _____ U2, the Irish rock band from Dublin perform a concert in Beijing, tell me in advance.
14. —Can’t you read the sign, sir? No parking here!—_____.
13. They only say such unkind things about you out of ____ envy, because you are ____ success as a writer.