Which is not true A) they are currently only in mesples art

B) they contain magnetic particles.

C) they were developed in nasa scientists

D) they can be controlled by magnets.

clinically, some people often have repeated allergies, eczema and respiratory infections or other parts of the infection, in this case, in addition to some routine tests such as tests for white blood cells, immunoglobulin series, lymphocyte subsets, etc., the five immune immunoglobulin tests are also necessary.

the answer is:

carbon dioxide