i suppose it's kondrat-krapiva, is that the correct answer, yes, kondrat, krapiva, i'm very surprisedt there is an object familiar to you, the main substance of which is described by the formula kco3, what is it? chalk, yeah, arina, perhaps it's chalk, chalk, chalk, that is, we took such a large chest and put a small piece of chalk in there. he knows, let's check, yes, we are people with a big scope, it's chalk. the sixth question: what is equal to the sum of the angles of a convex heptagon? angelina, i'll assume 360°. 360, well, that is, well, yes, uh-huh, no, that's the wrong answer. sofia, maybe 900°. how did you count? may i ask? and the formula, in my opinion, is 180 multiplied by 7 - 2 in brackets, and seven is by the number of angles, absolutely correct, both the formula and the answer are 900°. i'm shocked, i didn't know that. the seventh question: what is the name of the element of an electric circuit that serves to close and open it? sofia, this is not batik, arina, painting, just painting, well, no, if everything were that simple, this the question would not have been in th