Economy of Nigeria imports a significant amount of food to sustain itself. However, efforts are being made towards making the country food sufficient again. Nigeria's proven oil reserves are estimated to be ; natural gas reserves are well over . Nigeria is a member of the Organization of Petroleum Exporting Countries (OPEC). The types of crude oil exported by Nigeria are Bonny light oil, Forcados crude oil, Qua Ibo crude oil and Brass River crude oil. Poor corporate relations with indigenous communities, vandalism of oil infrastructure, severe ecological damage, and personal security problems throughout the Niger Delta oil-producing region continue to plague Nigeria's
Types of trombone Types of trombone There are many different types of trombone. The most frequently encountered trombones today are the tenor and bass, though as with other Renaissance instruments such as the recorder, the trombone has been built in every size from piccolo to contrabass (pitch of brass instruments). See trombone for information about the instrument in general. The cimbasso is a brass instrument in the trombone family, with a sound ranging from warm and mellow to bright and menacing. It has three to six piston or rotary valves, a predominantly cylindrical bore, and in its modern incarnation is most often pitched