Q. Which two nations share the longest international border in the world?
Answer: Canada and USA
Notes: Canada-United States Border, also known as International Boundary, is the longest international border in the world between two countries. The total length covers are 8891 kilometres. The Canada Border Service Agency and US Customs and Border Protection regulate and monitor the legal passage through the International Boundary.

This question is part of 40000+ General Studies MCQ Series Course on GKToday Android app. Question Number: 124 in World Geography - Continents and Country Trivia in above course in App.