Past Simple
The doorbell____(ring) when I_____(take) a shower.
The doorbell rang when I was taking a shower.
Mr. and Mrs. Davis _____ (fall) when they ______ (dance).
Mr. and Mrs. David fell when they were dancing.
My sister ____ (exercise) when she ________ (break) her trousers.
My sister was exercising when she (break) her trousers.