_____the world began, nations have had difficulty in keeping peace with their neighbors.
举一反三
- 3. The United Nations _____ (be) an international organization to maintain world peace and security.
- It was reported that the UN had made ___ progress in keeping the peace in the region.
- 74（） A: have kept B: had kept C: have been keeping D: had been keeping
- Send us a message if you _____ any difficulty . A: have B: had C: will have D: have had
- I had some difficulty in carrying out the plan.（） A: making B: keeping C: implementing D: changing