Answer: D
Explanation: The Ghana Empire, properly known as Wagadou (as Ghana was the title of its ruler), was a West African empire located in the area occupied by present-day southeastern Mauritania and western Mali. Although complex societies based on trans-Saharan trade in salt and gold had existed in the region for centuries, the introduction of the camel to the western Sahara in the 3rd century CE, opened the way to great changes in the area that eventually became the Ghana Empire.
The Ghana Empire grew rich from increased trans-Saharan trade in gold and salt, allowing for larger urban centres to develop. With these commodities being transported and traded through Ghana, the Kingdom was able to become very wealthy by taxing the goods that came through the trade center. It also helped that Ghana had many trade routes that were well protected by its large military force as this encouraged other merchants to come to Ghana for trade.
Answer:
Untouchables - Considered subhuman, did worst possible work.
Untouchables exist outside the caste system of the Hindu religion because they are considered so low that some think them subhuman. As a result they are regularly subjected to abuse but there have been efforts to change their situation in recent years.
Brahmin - Priests and learned people.
This is the highest caste/ verna and consists of Priests, Advisors and learned people.
Shudra - Peasants and laborers
This is the lowest/ fourth caste and as seen, consists of Peasants and laborers. They do the menial work.
Vaishya - Farmers and merchants
This is the third highest caste/ verna. Consists of Farmers, traders and merchants.
Answer:
Photosynthesis play important role in the cycling of matter into and out of the organisms as photosynthesis is the process in which plants utilize carbon dioxide (CO2) and water (H2O) and releases oxygen (O2) and energy in the form of carbohydrate or sugar. Other organisms utilizes these oxygen and energy or carbohydrate for the chemical reaction in their body.
So, photosynthesis take carbon dioxide (CO2) and water (H2O) from outside as input and gives oxygen (O2) and energy as output.
By trading and Conquering
