instruction:
In this task, you're given a context, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both context and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the context or linked information.
question:
Context: The United States of America will compete at the 2015 World Championships in Athletics from August 22 to August 30 in Beijing, China. Link Information: China (), officially the People's Republic of China (PRC), is a country in East Asia and the world's most populous country, with a population of around /1e9 round 3 billion in 2017. Covering approximately 9600000 km2, i Answer: 9600000 km2
answer:
What is the size of the country that hosted the 2015 World Championships in Athletics?


question:
Context: He paid for the final extension of the Montgomery Canal from Berriew to Newtown Link Information: none Answer: none
answer:
Which city that the Montgomery Canal ran through after an extension has the largest population?


question:
Context: Minaj was one of the opening acts on Britney Spears' 2011 Femme Fatale Tour. Link Information: Opening acts.- Nicki Minaj
- Jessie and the Toy Boys
- Nervo
- DJ Pauly D
- Joe Jonas
- Destinee & Paris
- The Wanted
- Howie Dorough
- Teen Angels Answer: - Nicki Minaj
- Jessie and the Toy Boys
- Nervo
- DJ Pauly D
- Joe Jonas
- Destinee & Paris
- The Wanted
- Howie Dorough
- Teen Angels
answer:

Who were the opening acts on Britney Spoears' 201 Femme Fatale Tour?