Answer: a)Copper and tin
Explanation: Copper and tin came into use at very early ages in the form of utensils, ornament etc. They were discovered in a way that it is possible for the people of early ages to extract these metals and melt them to give it some kind of shapes and utilize it for their daily living.People also started using these metals in the form of alloys as well which expanded the used of metals like copper, tin , bronze etc. Thus, correct option is copper and tin.
Answer:the environmental factor that influences the amount of sunlight that reaches the underwater plants and animals are abiotic factors. Aquatic biomes are influenced by a series of abiotic factors. However, these factors differ since water has different physical and chemical properties than does air. Even if the water in a pond or other body of water is perfectly clear (there are no suspended particles), water, on its own, absorbs light. As one descends into a deep body of water, there will eventually be a depth which the sunlight cannot reach. While there are some abiotic and biotic factors in a terrestrial ecosystem that might obscure light (such as fog, dust, or insect swarms), usually these are not permanent features of the environment.
The best and most correct answer among the choices provided by the question is the third choice ( 3 ).
Polaris is known as the north star pointing to the geographic north.
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Answer:
The movement by people from one place to another with the intentions of settling, permanently in the new location is called migration. Migration may be by individuals, family units or in groups. Most of the people get migrated for employment, in present scenario
Answer:
Social harmony is the living together of people of a particular social group with love, care, respect and brotherhood, regardless of their religion, region, caste, gender, colour etc.