1. When I was (Past Simple) on the Black Sea last summer I swam (Past Simple) in the sea every day. When we came (Past Simple) to the beach our friends were already swimming (Past Continuous) in the sea.2. Yesterday when I was listening (Past Continuous) to the radio my brother phoned (Past Simple) me. Yesterday I listened (Past Simple) to the 10 o\'clock news on the radio and went (Past Simple) to bed.3. I was going (Past Continuous) to the office yesterday morning when I met (Past Simple) Mr. S. Yesterday I came (Past Simple) to the office at a quarter to 9. The secretary brought (Past Simple) me the mail and I went (Past Simple) through it.4. At a quarter to 9 yesterday my son was having breakfast (Past Continuous).