igy international geographical year international geophysical year
Related Translations:
地球: the earth; the globe◇地球扁率 compression [flattening] of the earth; 地球扁球体 earth spheroid; 地球变化磁场 variable magnetic field of the earth; 地球表面 earth surface; 地球波导 terrestrial waveguide; 地球测绘电子学