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.

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
What is the size of the country that hosted the 2015 World Championships in Athletics?

Context: She filled in as the ring announcer for SmackDown on the July 15 and November 11 episodes. Link Information: WWE SmackDown, also known as Friday Night SmackDown or simply SmackDown, is a professional wrestling television program that debuted on April 29, 1999 Answer: April 29, 1999
When did the show where Rhodes filled in as announcer 
 on the July 15 and November 11 debut?

Context: Columbia, formerly Wright's Ferry, is a borough (town) in Lancaster County, Pennsylvania, Link Information: As of the 2010 census, the population was 519,445. Answer: 519,445

What is the current population of the county where Columbia, PA is located?