D. None of these
- Approximate age of earth is ________?
- Blood which heart pumps to lungs is__________?
- The poorest region of the world is__________?
- Earth has an equatorial circumference?
- Average salinity or ratio of salt as per kilogram of water of ocean is__________?
- Which is the thinnest earth layer?
- The synonyms of Catastrophe is__________?
- One of the following ways of expressing the concentration of a solution does not depend on temperature. It is__________?
- Second highest layer of Earth’s atmosphere is known as?
- In what time sun rays reach to earth?
- What is the name of the central part of the earth?
- Who measured the radius of earth first?