The Heilongjiang River, also known as the Sino-Russian border river, has an annual freeze-up period that lasts up to six months. The area’s wind speed can sometimes reach up to level 8 and the river’s surface temperature can fall down to a staggering minus 50 degrees at the lowest. Generations of fearless officers and soldiers have made it their duty to strengthen and consolidate the borders, all the while battling the bitter cold. [Photo/Xinhua]