In this task, You are given an open-domain question that can be answered based on factual information. Your task is to provide \*short\* answer (in a few words only) for the given question. The short answer can be one or more entities or it can also be boolean \*yes\* or \*no\*.

[Q]: what is the primary type of mining that takes place under the bolivian mountain
[A]: silver


[Q]: how fast can sound travel in a second
[A]: 331.2 metres


[Q]: how much of the us national debt does china own
[A]:
about $1.18 trillion