What gas was in the apparatus before you started generating oxygen? where did it go?

To generate oxygen in an apparatus, the gas stored must have oxygen in it. Then the remainder gas is either burnt or released in air. CO2 is one gas that has oxygen. If the apparatus has CO2, I can generate oxygen. After taking oxygen from CO2 in the apparatus. The gas which remains is C that is carbon. This gas is released in the air mostly in open.

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.