Раскрыть скобки 1. i (not to see) him ever since i (to leave) moscow. he (to be interested) in different space systems ever since he (to read)a book about them last year. 2. we (to participate) in all the international expositions ever since the first one (to hold) in london in 1851. 3. many interesting international exhibitions (to hold) in sokolniky park ever since the first one (to hold) there in the early 60s.

1.haven't seen,left,is interested,read
2.have participated,held
3. have held,held

1. I haven't seen him ever since I left Moscow.
He is interested in different space systems ever since he read a book
about them last year.
2. We have participated in all the international expositions ever since the first one held in London in 1851.
3. Many interesting international exhibitions have held in Sokolniky Park ever since the first one held there in the early 60s.