1.What country sold a lot of...?
Argentina didn't sell a lot...
3. What did they discuss yesterday?
They didn't discuss...
4. I didn't change...
5. How many ways of doing this were there?
There weren't any ways...
7. Where did I speak over telephone to (yesterday)?
I didn't speak over...
8. Where was he?
He was not in the office.
9. What did they read last week?
They didn't read our...
10. My sister didn't go on several...
Написала, что знала. Троеточие означает то же самое, что и в изначальном предложении в упражнении.