a) 1) Did they go to Sochi last summer?
2) They went to Sochi last summer , didn't they ?
3) Who went to Sochi last summer?
4) Did they go to Sochi last summer, or last spring?
5) Where did they go last summer?
b) 1) What does she often us tell ?
2) When will have they built a house by that time?
3)who often tells funny stories to us?
4) When does she tells us funny stories
5) She often tells us funny stories, doesn't she ?
d)1) Are they waiting for you ?
2) They are waiting for you , aren't they ?
3) Whom they waiting ?
4) Who is waiting for you?
5) What are they doing?