Definition: 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: For nearly forty years, the United States has said categorically it would not tolerate totalitarian rule in its own backyard. It is the US economic and political embargo which has kept Cuba in a box.
Output:
What event has already happened?