Преобразуйте все исчисляемые существительные в единственном числе во множественное 1. The foot is sore 2. There is man

1. The foot is sore. The feet are sore.
2. There is man behind you. There are men behind you.
3. This isn’t a mouse. These aren’t mice.
4. This hero is unknown. These heroes are unknown.
5. The mystery of the case was revealed. The mysteries of the cases were revealed.
6. The friend of mine is coming to stay at the weekend. The friends of mine are coming to stay at the weekend.
7. What is the chance of success? What are the chances of success?
8. There was a small loss. There were small losses.
9. Crime is a problem in most big cities. Crime (преступность) – неисчисляемое существительное.
10. What is the criterion for this estimation? What are the criteria for these estimations?