Teacher:In this task, you're given a statement, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Teacher: Now, understand the problem? Solve this instance: Context: As a result of negotiations and the 1984 agreement between China and Britain, Hong Kong was returned to China Link Information: This event ended 156 years of British colonial rule in Hong Kong. Question: How long had Britain had control of Hong Kong before returning it to China?
Student:
Answer: 156 years