1. When (did she decide / had she decided) to take a course in che-
mistry?
2. G. B. Shaw (wrote / has written) a lot of plays.
3. The applicants were happy to hear that they (passed / had passed)
the centralized test successfully.
4. (Did you meet / Have you met) anyone interesting at the recep-
tion?
5. Mr. Billboard (had been thinking / thought) his decision over du-
ring the lunch break.
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