Explanation:
(a)
There is inverse relation between concentration of aluminium and pH value and it can lead to aluminium toxicity. In this case it will dominate in the form of Hydroxy- aluminium, Al³⁺ cation and polynuclear species.
(b)
Various minerals are brought to the soil during its formation . As we know the pedogenesis process starts due to erosion of the rocks and rocks contain various minerals, of which aluminium is also a part. With time, aluminium gets dissolved in water and the soil and as the rocks become soil after going through various processes like traction, solution etc, it gets aluminium ions also with it.
Tourism and oil drilling are definitely not traditional activities, rather they are modern activities that started with the spread of the technology - they can't be the correct answer.
Traditionally, people from central Asia were leading rather a nomadic lifestyle and were tending to life stock - the correct answer is B
Answer:
Explanation:
The first question is option 3 and the second is option 2 and 3
The most active volcanoes are located in South America and the bottom of North America
Answer:
Options (1), (2) and (3)
Explanation:
Alfred Wegener was the person who first invented the continental drift theory. He observed that the continents move from one place to another with respect to a fixed point. He put forward many pieces of evidence but he was unable to explain the main mechanism that is responsible for these motion of continents.
The pieces of evidence that were given by Alfred Wegener supporting the continental drift theory are-
(a) The continents move slowly and continuously from one place to another and the edges of these continents perfectly match with the other.
(b) Similar fossil assemblages were found in currently separated continents.
(c) Similar rock types are also found and suggested that the continents were once all together forming a huge landmass which is known as the Pangaea.
Later this theory was modified into a more simple and universally accepted theory which is commonly known as the Plate tectonic theory.
Hence, the correct answers are options (1), (2) and (3).