Make up sentences. i was in london yesterday they were in africa last summer mary in canada last week my parents in russia last weekend bill in america last month

I was in London ( Africa, Canada, Russia, America)  yesterday (last summer, last week, last weekend, last month)
They were in London ( Africa, Canada, Russia, America) yesterday (last summer, last week, last weekend, last month)
Mary  was in London ( Africa, Canada, Russia, America) yesterday (last summer, last week, last weekend, last month)
My parents were in London ( Africa, Canada, Russia, America) yesterday (last summer, last week, last weekend, last month)
Bill was in London ( Africa, Canada, Russia, America) yesterday (last summer, last week, last weekend, last month) 

P.S. Во множественном числе употребляется форма WERE.  В единственном - WAS.
P.S.S. Выделенные курсивом слова ты можешь заменить, если захочешь, на слова, указанные в скобках