TASK DEFINITION: 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\*.
PROBLEM: the shortest distance between two points on the earth's surface is

SOLUTION: great-circle distance

PROBLEM: what is the primary type of mining that takes place under the bolivian mountain

SOLUTION: silver

PROBLEM: when did the final surrender of the civil war occur

SOLUTION:
April 9, 1865