3.
3) founded
4) was
5) didn't have
6) climbed
7) runed
8) searched
9) tied
10) broke out
11) rushed
12) exploded
13) sunk
14) happend
15) existed
4.
He was studying when the lights went out
She was cooking wile we were watching tv
They were playing football when the lights went out
The phone rang when he was sitting on the table
Tom and i were walking in the forest when the lightning stroke.