sentences:  The Congolese government started negotiating membership in the Organization for the Harmonization of Business Law in Africa (OHADA), in 2009.The Democratic Republic of Congo is widely considered one of the world's richest countries in natural resources; its untapped deposits of raw minerals are estimated to be worth in excess of US$24 trillion.The Congo has 70% of the world's coltan, a third of its cobalt, more than 30% of its diamond reserves, and a tenth of its copper.