Detailed Instructions: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Problem:(CNN) -- Vito Maggiolo, an assignment editor in Washington who has been with CNN since the network started in 1980, was sent to Beijing in the spring of 1989 to help cover the historic visit of Soviet leader Mikhail Gorbachev to China -- like everyone else who was sent to Beijing. Vito Maggiolo (right) argued that a letter requiring CNN to stop broadcasting did not have the correct seal, or "chop." "All of us went to China prepared for and expecting to cover what for us was a fairly routine, scheduled, structured event," said Maggiolo. "Then we had this whole event in the square materialize and suddenly ... we found ourselves covering a mini-revolution."Vito Maggiolo was sent to Beijing to help cover Mikhail Gorbachev's visit to China"We found ourselves covering a mini-revolution," he saidWhen Chinese officials tried to stop CNN broadcasting, he challenged themHe argued, without success, that the letter did not have the correct "chop" or seal 
 Question:Maggiolo missed the actual crackdown -- his visa had expired so he was pulled out a few days before June 4 -- but what he'll always be remembered for, he says, is his last-ditch role in the confrontation between CNN and the Chinese authorities that ended with the _ halting CNN's live transmission on the morning of May 20.
Solution:
China