Усны худгийн өрмийн машинуудын тойм |Шенглида
In the 2nd century BC, China has used manpower and used bamboo bow elastic force to make the cone drill bit impact the ground to drill. Later, it was used in rural China for a long time. It was not until the 1950s that wire rope percussion drilling rigs were introduced from abroad. In the early 1...