Instructions: In this task, a passage will be given and the goal is to generate a question about temporal relations based on that passage. A temporal relation describes the relation between two things with respect to time e.g., something happens/starts/terminates/... immediately/shortly/usually/... before/after/during/... something else.
Your question should include an event, or ask about an event, and should not be a yes/no question.
Input: Passage: Kosovo has been run by a United Nations mission since 1999, when a NATO bombing campaign ended a crackdown by Belgrade on separatist ethnic Albanian rebels in the province. The UN envoy to Kosovo, Martti Ahtisaari, began negotiations in February with Serbian and Kosovo authorities to define the future status of the province.
Output:
What event has already finished?