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.

Q: Context: He commanded the U.S. forces in the Battle of Tirad Pass, 2 December 1899, where General Gregorio del Pilar was killed Link Information: He was promoted to brigadier-general after this event. Answer: 1 

A: How long had Gregorio del Pilar been a General for when he was killed?
****
Q: Context: such as the Swiss band Hellhammer (later to become Celtic Frost) Link Information:  Formed in 1981 as Hellhammer, the band became Celtic Frost in 1984 Answer: 1984

A: In what year did Hellhammer become Celtic Frost?
****
Q: Context: He served for four years until he joined the 13th Hussars as a second lieutenant in 1880 Link Information: 1871 Lt-Col Fitzroy Maclean Answer: Lt-Col Fitzroy Maclean

A:
Who commanded the 13th Hussars when Anstruther-Gray joined as a second lieutenant?
****