Q: You need to read the given passage and construct a question about the information present in the passage. The question should be answerable from the passage. Most importantly, only those questions are allowed whose answers cannot be determined from a single sentence. Do not generate questions that require only a single sentence to answer. Instead, try to combine two sentences and create a question from that combination. Do not create open-ended questions, i.e., the answers to them cannot be found precisely from the information provided in the passage.
Paragraph- Sent 1: Into the 21st Century: As 1997 drew nearer, it became clear that the Chinese government had no intention of renewing the 99-year lease on the New Territories.
Sent 2: Negotiations began, and in 1984 Prime Minister Margaret Thatcher signed the Sino-British Joint Declaration, in which Britain confirmed the transfer of the New Territories and all of Hong Kong to China in 1997.
Sent 3: For its part, China declared Hong Kong a "Special Administrative Region" and guaranteed its civil and social system for at least 50 years after 1997.
Sent 4: Although China's Basic Law promised that Hong Kong's existing laws and civil liberties would be upheld, refugees began flowing the other way.
Sent 5: The British Nationality Act (1981) had in effect prevented Hong Kong citizens from acquiring British citizenship, and thousands of people, anxious about their future under China's rule, were prompted to apply for citizenship elsewhere, notably in Canada and Australia.
Sent 6: The protests in 1989 in Beijing's Tiananmen Square sparked sympathy marches in Hong Kong, and further increased tension with China.
Sent 7: Some companies moved their headquarters out of Hong Kong.
Sent 8: Ironically, as the handover approached, the British granted the Hong Kong Chinese more political autonomy than they had done since the colony was founded, including such democratic reforms as elections to the Legislative Council.
Sent 9: Since the handover in July 1997, China has generally followed a hands-off policy.
Sent 10: Many who fled have returned.
Sent 11: What controls heartbeats in Hong Kong are the fluctuations of the Hang Seng Index, foreign currency exchange rates, and skyrocketing property prices.
Sent 12: In short, the status quo prevails.
Sent 13: Everybody hopes Hong Kong will remain stable, but everyone also has their doubts.
Sent 14: In the meantime, the philosophy is to seize present-day opportunities in the thriving economy.
A:
what two countries were involved in the Sino-British Joint Declaration in 1997?