Why are runners in the 100 meter dash and marathon runners forced to employ different running strategies in order to win their respective races?

Because different running strategies will help the runners win the race. And also help them become better runners.

Hope this helps

Cause u could be the best at only one and it wouldnt be fair to label u the best
 

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.