要求对代码进行小幅修改

Question

我不是 TeX 的专家用户。我想根据自己的需要对下面的代码进行一些小改动。选项是

\choise0 for wrong answer and
\choice1 for the correct answer

我该怎么做

 \choise for wrong answer and
 \correctchoice for the correct answer

我也想在最后显示答案。感谢您的所有帮助和时间。

\documentclass{article}
\usepackage{environ}
\newlength{\choiceslen}

\newif\ifshowcorrect
\newcounter{choices}
\newcommand{\choicefinal}[1]{%
\ifnum\value{choices}>0 \hfill\fi\egroup
\hspace{0pt}%
\hbox to\choiceslen
\bgroup
\stepcounter{choices}%
\ifcase#1\relax
(\Alph{choices})%
\else
\ifshowcorrect
  \expandafter\underline
\fi
{(\Alph{choices})}%
\fi\space}
\newcommand{\choicetemp}[1]{\stepcounter{choices}\space(\Alph{choices})\cr}

\NewEnviron{choices}
{\setcounter{choices}{0}%
\let\choice\choicetemp
\settowidth{\choiceslen}{\vbox{\halign{##\hfil\cr\BODY\crcr}}}
\ifdim\choiceslen>.5\textwidth
\setlength{\choiceslen}{\textwidth}%
\else
\ifdim\choiceslen>.25\textwidth
  \setlength{\choiceslen}{.5\textwidth}%
\else
  \setlength{\choiceslen}{.25\textwidth}%
\fi
\fi
\let\choice\choicefinal
\setcounter{choices}{0}%
\begin{flushleft}
\bgroup\BODY\hfill\egroup
\end{flushleft}}

\begin{document}
\showcorrecttrue
\begin{choices}
\choice0 apple
\choice1 banana
\choice0 orange
\choice0 pear
\end{choices}


\begin{choices}
\choice0 apple
\choice0 banana
\choice0 orange  
\choice1 pear
\end{choices}

%\showcorrecttrue

\begin{choices}
\choice0 apple
\choice0 banana
\choice1 orange, eeeeeeeee, eeeeeeeee, eeeeeeeee
\choice0 pear
\end{choices}

\begin{choices}
\choice0 apple
\choice1 banana
\choice0 orang, eeeeeeeee
\choice0 pear
\end{choices}


\begin{choices} 
\choice0 
\begin{minipage}[t]{\textwidth}
This is a very long question. This is a very long question. This is a very long question. This is a very long question. This is a very long question. This is a very long question. 
\end{minipage}
\choice0 
\begin{minipage}[t]{\textwidth}
This is a very long question. This is a very long question. This is a very long question. This is a very long question. This is a very long question. This is a very long question. 
\end{minipage}
\choice0 
\begin{minipage}[t]{\textwidth}
This is a very long question. This is a very long question. This is a very long question. This is a very long question. This is a very long question. This is a very long question. 
\end{minipage} 
\choice0 
\begin{minipage}[t]{\textwidth}
This is a very long question. This is a very long question. This is a very long question. This is a very long question. This is a very long question. This is a very long question. 
\end{minipage}
\end{choices}
\end{document}

Answer 1

下面我定义\shorthandchoice更新\choice默认为\choice{0}和\correctchoice为\choice{1}：

\documentclass{article}

\usepackage{environ}
\newlength{\choiceslen}

\newif\ifshowcorrect
\newcounter{choices}
\newcommand{\choicefinal}[1]{%
  \ifnum\value{choices}>0 \hfill\fi\egroup
    \hspace{0pt}%
    \hbox to\choiceslen
    \bgroup
    \stepcounter{choices}%
    \ifcase#1\relax
      (\Alph{choices})%
    \else
      \ifshowcorrect
        \expandafter\underline
      \fi
      {(\Alph{choices})}%
    \fi\space
}
\newcommand{\choicetemp}[1]{%
  \stepcounter{choices}%
  \space(\Alph{choices})\cr
}

\NewEnviron{choices}{%
  \setcounter{choices}{0}%
  \let\choice\choicetemp
  \shorthandchoice% <---------- Add \choice shorthand
  \settowidth{\choiceslen}{\vbox{\halign{##\hfil\cr\BODY\crcr}}}
  \ifdim\choiceslen>.5\textwidth
    \setlength{\choiceslen}{\textwidth}%
  \else
    \ifdim\choiceslen>.25\textwidth
      \setlength{\choiceslen}{.5\textwidth}%
    \else
      \setlength{\choiceslen}{.25\textwidth}%
    \fi
  \fi
  \let\choice\choicefinal
  \shorthandchoice% <---------- Add \choice shorthand
  \setcounter{choices}{0}%
  \begin{flushleft}
    \bgroup\BODY\hfill\egroup
  \end{flushleft}
}

\newcommand{\shorthandchoice}{%
  \let\oldchoice\choice
  \renewcommand{\choice}{\oldchoice{0}}
  \def\correctchoice{\oldchoice{1}}
}

\begin{document}

\showcorrecttrue
\begin{choices}
  \choice apple
  \correctchoice banana
  \choice orange
  \choice pear
\end{choices}

\begin{choices}
  \choice apple
  \choice banana
  \choice orange  
  \correctchoice pear
\end{choices}

%\showcorrecttrue

\begin{choices}
  \choice apple
  \choice banana
  \correctchoice orange, eeeeeeeee, eeeeeeeee, eeeeeeeee
  \choice pear
\end{choices}

\begin{choices}
  \choice apple
  \correctchoice banana
  \choice orang, eeeeeeeee
  \choice pear
\end{choices}

\begin{choices} 
  \choice 
  \begin{minipage}[t]{\textwidth}
    This is a very long question. This is a very long question. This is a very long question. 
    This is a very long question. This is a very long question. This is a very long question. 
  \end{minipage}
  \choice 
  \begin{minipage}[t]{\textwidth}
    This is a very long question. This is a very long question. This is a very long question. 
    This is a very long question. This is a very long question. This is a very long question. 
  \end{minipage}
  \choice 
  \begin{minipage}[t]{\textwidth}
    This is a very long question. This is a very long question. This is a very long question. 
    This is a very long question. This is a very long question. This is a very long question. 
  \end{minipage} 
  \choice 
  \begin{minipage}[t]{\textwidth}
    This is a very long question. This is a very long question. This is a very long question. 
    This is a very long question. This is a very long question. This is a very long question. 
  \end{minipage}
\end{choices}

\end{document}