Questions

The mesosphere lies above the stratosphere and extends to an altitude of about 85 km. This is layer is often referred to as the cold layer, as the lowest readings in the atmosphere are found here.

Temperature decreases with height, reaching a minimum average value of -90 ºC at the top of the layer.

Sport played on horseback is called as Polo. It is the national sport of Iran.

Manabendra Nath Roy, known as M.N. Roy was an Indian revolutionary, radical activist and political theorist, as well as a noted philosopher in the 20th century. Roy was a founder of the Mexican Communist Party and the Communist Party of India.

Before transferring the fish, the position is the man with the fish and the bucket of water. After transferring the position is: the man without the fish, but the fish inside the water in the bucket. Thus to know  whether there is any change in weight, it is enough to consider whether there is any change in weight when the fish in air is transferred into the water. The answer is there is no change as when in water though it loses weight due to upthrust of water on it, the level of water increases and exerts an equal force at the bottom.So, (c) is correct.

Before transferring the fish, the position is the man with the fish and the bucket of water. After transferring the position is : the man without the fish, but the fish inside the water in the bucket. Thus to know whether there is any change in weight, it is enough to consider whether there is any change in weight when the fish in air is transferred into the water. The answer is there is no change as when in water though it loses weight due to upthrust of water on it, the level of water increases and exerts an equal force at the bottom

The population is the smallest unit of living organisms that can undergo evolution.