Explain why convection happens more efficiently in water or air than it does in rock

A rock is actually an object so there are a lot of molecules that are stuck together and cannot let most of the heat pass through it. While in water and air, the molecules are more free-willing and more spacious so I think that is why convection travels faster and more efficiently in water and air than in rocks.

answer: - b cells

explanation: -

there are many types of white blood cells present in our body. one such class of white blood cells are the lymphocytes. the b cells belong to the lymphocyte class of wbcs. the b cells perform their action against the pathogen by producing specialised proteins called as antibodies. these antibodies are produced as and when the b cells encounter pathogens in response to the antigens present on the surface of the pathogen. these antibodies bind to the antigens present on the pathogen and then, target them for destruction by other cells of the immune system.

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.