TASK DEFINITION: In this task, we ask you to write an answer to a question about the events that may happen before or after a certain event. For example, "earning money" usually appears before "spending money". Note that a lot of the questions could have more than one correct answer. We only need a single most-likely answer. Please try to keep your "answer" as simple as possible. Concise and simple "answer" is preferred over those complex and verbose ones.
PROBLEM: Sentence: One result was two NSC-led interagency trips to Persian Gulf states in 1999 and 2000. 
Question: Where did the NSC go after they were done with their trip?

SOLUTION: united states.

PROBLEM: Sentence: For example, you can undo the tarnish on copper pennies by placing them in vinegar. 
Question: What do you have to do after placing the pennies in vinegar?

SOLUTION: let them stand there.

PROBLEM: Sentence: The properties of matter depend on the types of atoms that matter is made of. 
Question: When do the properties of matter change?

SOLUTION:
they change when the type of atoms change.

