The best answer is reduction in acid rain.
Acid rain is rainfall which has been rendered acidic by pollutants in the atmosphere. This kind of rain is typically harmful to forests and lakes.
The main cause of acid rain is human activities. The burning of fossil fuels such coal in electrical generating plants and crude oil products such as gasoline and diesel in car engine releases sulphur dioxide and nitrogen oxide into the atmosphere.
These compounds mix with water very high up in the atmosphere and form acid pollutants which fall on the ground as acid rain.
Use of clean energy will eliminate burning of fossil fuels and thus no acid rain will be produced.
Answer:
The largest continent of the world is Asia
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.