Economic undeveloped regions
economically undeveloped area
Percentage of undeveloped grain
remote and undeveloped areas
undeveloped
欠
未
不
未开发的
未显影的
不发达的
欠发达
不发达
未展开射丛
undeveloped curved surface
undeveloped oil-bearing reservoirs
undeveloped proved reserves
Absorbed hydrocarbons in soils
acid brown forest soils