Question and answer two columns

Question

I have searched the internet and found similar things but not an exact one. I want to create environments and other stuff required to make a pdf file as in the image. First comes the subsection title with numbering (④窒素 in the picture), and then the problems and corresponding answers (numberd like (1) and others in the picture) with the same height in both columns. Problems have a checkbox in front of them. The dotted lines in the image appear when a new subsection appears. Preferably, outside the two columns, I want to add a section title like "Introductory Chemistry". And the color of the answer except the numbering should be red.

Which packages do you suggest using?

I've tried this page but it ended up like

\documentclass[landscape,12pt]{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage[showframe,a4paper]{geometry} % change to a3paper if needed
\usepackage{etoolbox}
\usepackage{enumitem}
\newtoggle{morethanoneparagraph}
\togglefalse{morethanoneparagraph}
\newcommand{\mycolumnwidth}{0.45\textwidth}
\newenvironment{qanda}{% Q&A
    \newcommand\nextpart{%
        \end{enumerate}
        \end{minipage}
        \begin{minipage}[t]{\mycolumnwidth}
        \iftoggle{morethanoneparagraph}{%
            \begin{enumerate}[label=\roman.,resume=q] 
                \item
        }{%
            \global\toggletrue{morethanoneparagraph}
            \begin{enumerate}[label=\roman.,series=q] 
                \item
        }
    }
    \begin{minipage}[t]{\mycolumnwidth}
    \iftoggle{morethanoneparagraph}{
        \begin{enumerate}[label=\arabic.,resume=a] 
            \item 
    }{
        \begin{enumerate}[label=\arabic.,series=a] 
            \item 
    }
}{
    \end{enumerate}
    \end{minipage}
    \vspace{\baselineskip}
}
\setlength{\parindent}{0pt}
\begin{document}
\begin{qanda}
    Find a nonzero polynomial in $\mathbb{F}_2\left[x_1,x_2,\cdots,x_n\right]$ which is zero as a function.
    \nextpart
    $x_1 x_2 \cdots x_n \left(x_1+x_2\right)$
\end{qanda}
\begin{qanda}
        Find a nonzero polynomial in $\mathbb{F}_p[x]$ that vanishes at all points of $\mathbb{F}_p[x]$
        \nextpart
        $x^p-x$
\end{qanda}
\end{document}