use the past indefinite or the past perfect in adverbial clauses of time.
1.when mr.scott (saw/had seen) he visitor, he got very angry.
2.as soon as the orchestra (began/had begun) to play, john left the hall.
3.when she (tidied up/had tidied up) the bedrooms, she went downstairs to have a rest.
4.when the students (took/had taken) their seats, the professor began his lecture.
5.when they were leaving the restaurant, it began to rain havily and they (had/had had) to go back.
6.when dikran (made/had made) his speech, everybody began to applaud.
7.he called me as soon as he (got/had got) home.
8.when they (knew/had known) me for a year, they invited me to dinner.
9.he refused to leave until he (saw/had seen) the manager.
10.he (was/had been) in the army for a year when his father died.
