1)
1.She was surfing when the shark attacked her.
2.He was dancing at a party when he met his girlfriend.
3.I was having a picnic when i saw my sister
4.When they saw the shark they were swiming in the sea.
5.Susan arrived while i was having dinner.
6.He was playing football when he broke his leg.
7.I was waited for my friends when the bus arrived.
8.When i got back my mum was cooking dinner.
2)
did you do
went to a party
did
enjoyed
met
was talking
asked
lives
does he know
go to
11 не знаю, to see не употребляется в progressive
are going to