Help me with the topic of C language. .

C (upstairs, you can't fool people, you can obviously start with an underscore, and double should be 8 knots) dacb

D (I don't think b is either. D is a double quotation mark. . . )cdad

acbba

(I'm not sure about the question 16) 17-20 cccd

I'm totally different from the one upstairs. He must have written it casually. I don't believe you think his first question is wrong. . .