what is 13c breath test

what is 13c breath test What is Benidict test? IQ test What is it? what is the resazurin test? My breath is your breath What is the test good for?意思? what i need is the air I breath and Ithe place rest my head是 Knowing what the test will cover is half the battle My fight is your fight.My breath is your breath. The air is to ( A.breath B.be breath What results is a test.请问,这句话What是充当什么成分? IQ test~~~If FRTZZ is the code for ESSAY, what is the code f