\documentclass[12pt,a4paper]{exam}
\usepackage{amsmath,amsthm,amsfonts,amssymb,dsfont}
\usepackage{ifthen}
\usepackage[margin = 0.8in]{geometry}
\usepackage{gensymb}
\newcommand{\ttt}{\textbf{- T}}
\newcommand{\fff}{\textbf{- F}}
\newcommand{\fbb}[1]{\textbf{\underline{#1}}}
% Accumulate the answers. Unmodified from Phil Hirschorn's answer
% https://tex.stackexchange.com/questions/15350/showing-solutions-of-the-questions-separately/15353
\newbox\allanswers
\setbox\allanswers=\vbox{}
\newenvironment{answer}
{%
\global\setbox\allanswers=\vbox\bgroup
\unvbox\allanswers
}%
{%
\bigbreak
\egroup
}
\newcommand{\showallanswers}{\par\unvbox\allanswers}
% End Phil's answer
% Is there a better way?
\newcommand*{\getanswer}[5]{%
\ifthenelse{\equal{#5}{a}}
{\begin{answer}\thequestion. (a)~#1\end{answer}}
{\ifthenelse{\equal{#5}{b}}
{\begin{answer}\thequestion. (b)~#2\end{answer}}
{\ifthenelse{\equal{#5}{c}}
{\begin{answer}\thequestion. (c)~#3\end{answer}}
{\ifthenelse{\equal{#5}{d}}
{\begin{answer}\thequestion. (d)~#4\end{answer}}
{\begin{answer}\textbf{\thequestion. (#5)~Invalid answer choice.}\end{answer}}}}}
}
\setlength\parindent{0pt}
%usage \choice{ }{ }{ }{ }
%(A)(B)(C)(D)
\newcommand{\fourch}[5]{
\par
\begin{tabular}{*{4}{@{}p{0.23\textwidth}}}
(a)~#1 & (b)~#2 & (c)~#3 & (d)~#4
\end{tabular}
\getanswer{#1}{#2}{#3}{#4}{#5}
}
%(A)(B)
%(C)(D)
\newcommand{\twoch}[5]{
\par
\begin{tabular}{*{2}{@{}p{0.46\textwidth}}}
(a)~#1 & (b)~#2
\end{tabular}
\par
\begin{tabular}{*{2}{@{}p{0.46\textwidth}}}
(c)~#3 & (d)~#4
\end{tabular}
\getanswer{#1}{#2}{#3}{#4}{#5}
}
%(A)
%(B)
%(C)
%(D)
\newcommand{\onech}[5]{
\par
(a)~#1 \par (b)~#2 \par (c)~#3 \par (d)~#4
\getanswer{#1}{#2}{#3}{#4}{#5}
}
\newlength\widthcha
\newlength\widthchb
\newlength\widthchc
\newlength\widthchd
\newlength\widthch
\newlength\tabmaxwidth
\setlength\tabmaxwidth{0.96\textwidth}
\newlength\fourthtabwidth
\setlength\fourthtabwidth{0.25\textwidth}
\newlength\halftabwidth
\setlength\halftabwidth{0.5\textwidth}
\newcommand{\choice}[5]{%
\settowidth\widthcha{AM.#1}\setlength{\widthch}{\widthcha}%
\settowidth\widthchb{BM.#2}%
\ifdim\widthch<\widthchb\relax\setlength{\widthch}{\widthchb}\fi%
\settowidth\widthchb{CM.#3}%
\ifdim\widthch<\widthchb\relax\setlength{\widthch}{\widthchb}\fi%
\settowidth\widthchb{DM.#4}%
\ifdim\widthch<\widthchb\relax\setlength{\widthch}{\widthchb}\fi%
% These if statements were bypassing the \onech option.
% \ifdim\widthch<\fourthtabwidth
% \fourch{#1}{#2}{#3}{#4}{#5}
% \else\ifdim\widthch<\halftabwidth
% \ifdim\widthch>\fourthtabwidth
% \twoch{#1}{#2}{#3}{#4}{#5}
% \else
% \onech{#1}{#2}{#3}{#4}{#5}
% \fi\fi\fi}
% Allows for the \onech option.
\ifdim\widthch>\halftabwidth
\onech{#1}{#2}{#3}{#4}{#5}
\else\ifdim\widthch<\halftabwidth
\ifdim\widthch>\fourthtabwidth
\twoch{#1}{#2}{#3}{#4}{#5}
\else
\fourch{#1}{#2}{#3}{#4}{#5}
\fi\fi\fi}
\begin{document}
\begin{questions}
\question For airborne sounds, the reference sound pressure taken to measure the sound pressure level is (\textbf{1991})
\choice{$2\:X\:10^3\:N/m^2$}{$2\:X\:10^{-3}\:N/m^2$}{$2\:X\:10^5\:N/m^2$}{$2\:X\:10^{-5}\:N/m^2$}{d}
\question In a force-feed lubrication system adopted in the tractor engine, the type of pump generally used is
\choice{Centrifugal pump}{Gear pump}{Rotary vane pump}{Plunger pump}{b}
\question The type of bearing used to support the disc on a standard disc plough is
\choice{Bush bearing}{Plain roller bearing}{Tapered roller bearing}{Ball bearing}{c}
\end{questions}
%\newpage %Uncomment to put on new age
\newpage
Answer Key:
\bigskip
\showallanswers % Phil Hirschorn
\end{document}
答案1
以下内容不提供保证：
\documentclass[12pt,a4paper]{exam}
\usepackage[dvipsnames]{xcolor}
\usepackage[colorlinks=true]{hyperref}
\usepackage{amsmath,amsthm,amsfonts,amssymb,dsfont}
\usepackage{ifthen}
\usepackage[margin = 0.8in]{geometry}
\usepackage{gensymb}
\newcommand{\ttt}{\textbf{- T}}
\newcommand{\fff}{\textbf{- F}}
\newcommand{\fbb}[1]{\textbf{\underline{#1}}}
% Accumulate the answers. Unmodified from Phil Hirschorn's answer
% https://tex.stackexchange.com/questions/15350/showing-solutions-of-the-questions-separately/15353
\newbox\allanswers
\setbox\allanswers=\vbox{}
\newenvironment{answer}
{%
\global\setbox\allanswers=\vbox\bgroup
\unvbox\allanswers
}%
{%
\bigbreak
\egroup
}
\newcommand{\showallanswers}{\par\unvbox\allanswers}
% End Phil's answer
\makeatletter
\definecolor{getanscolor}{named}{ForestGreen}
\newcommand\linktoanswer[1]{%
\begingroup
\hypersetup{linkcolor=getanscolor, linkbordercolor=getanscolor}%
\hyperref[{question@\arabic{question}Ans}]{#1}%
\endgroup
}
\newcommand\linktoquestion[1]{%
\begingroup
\hypersetup{linkcolor=getanscolor, linkbordercolor=getanscolor}%
\hyperref[question@\arabic{question}]{#1}%
\endgroup
}%
\def\questionlabel{\linktoanswer{\thequestion.}}
% Is there a better way?
\newcommand*{\getanswer}[5]{%
\ifthenelse{\equal{#5}{a}}
{\begin{answer}\phantomsection\label{question@\arabic{question}Ans}%
\linktoquestion{\thequestion. (a)~#1}\end{answer}}
{\ifthenelse{\equal{#5}{b}}
{\begin{answer}\phantomsection\label{question@\arabic{question}Ans}%
\linktoquestion{\thequestion. (b)~#2}\end{answer}}
{\ifthenelse{\equal{#5}{c}}
{\begin{answer}\phantomsection\label{question@\arabic{question}Ans}%
\linktoquestion{\thequestion. (c)~#3}\end{answer}}
{\ifthenelse{\equal{#5}{d}}
{\begin{answer}\phantomsection\label{question@\arabic{question}Ans}%
\linktoquestion{\thequestion. (d)~#4}\end{answer}}
{\begin{answer}\textbf{\thequestion. (#5)~Invalid answer choice.}\end{answer}}}}}
}
\makeatother
\setlength\parindent{0pt}
%usage \choice{ }{ }{ }{ }
%(A)(B)(C)(D)
\newcommand{\fourch}[5]{
\par
\begin{tabular}{*{4}{@{}p{0.23\textwidth}}}
(a)~#1 & (b)~#2 & (c)~#3 & (d)~#4
\end{tabular}
\getanswer{#1}{#2}{#3}{#4}{#5}
}
%(A)(B)
%(C)(D)
\newcommand{\twoch}[5]{
\par
\begin{tabular}{*{2}{@{}p{0.46\textwidth}}}
(a)~#1 & (b)~#2
\end{tabular}
\par
\begin{tabular}{*{2}{@{}p{0.46\textwidth}}}
(c)~#3 & (d)~#4
\end{tabular}
\getanswer{#1}{#2}{#3}{#4}{#5}
}
%(A)
%(B)
%(C)
%(D)
\newcommand{\onech}[5]{
\par
(a)~#1 \par (b)~#2 \par (c)~#3 \par (d)~#4
\getanswer{#1}{#2}{#3}{#4}{#5}
}
\newlength\widthcha
\newlength\widthchb
\newlength\widthchc
\newlength\widthchd
\newlength\widthch
\newlength\tabmaxwidth
\setlength\tabmaxwidth{0.96\textwidth}
\newlength\fourthtabwidth
\setlength\fourthtabwidth{0.25\textwidth}
\newlength\halftabwidth
\setlength\halftabwidth{0.5\textwidth}
\newcommand{\choice}[5]{%
\settowidth\widthcha{AM.#1}\setlength{\widthch}{\widthcha}%
\settowidth\widthchb{BM.#2}%
\ifdim\widthch<\widthchb\relax\setlength{\widthch}{\widthchb}\fi%
\settowidth\widthchb{CM.#3}%
\ifdim\widthch<\widthchb\relax\setlength{\widthch}{\widthchb}\fi%
\settowidth\widthchb{DM.#4}%
\ifdim\widthch<\widthchb\relax\setlength{\widthch}{\widthchb}\fi%
% These if statements were bypassing the \onech option.
% \ifdim\widthch<\fourthtabwidth
% \fourch{#1}{#2}{#3}{#4}{#5}
% \else\ifdim\widthch<\halftabwidth
% \ifdim\widthch>\fourthtabwidth
% \twoch{#1}{#2}{#3}{#4}{#5}
% \else
% \onech{#1}{#2}{#3}{#4}{#5}
% \fi\fi\fi}
% Allows for the \onech option.
\ifdim\widthch>\halftabwidth
\onech{#1}{#2}{#3}{#4}{#5}
\else\ifdim\widthch<\halftabwidth
\ifdim\widthch>\fourthtabwidth
\twoch{#1}{#2}{#3}{#4}{#5}
\else
\fourch{#1}{#2}{#3}{#4}{#5}
\fi\fi\fi}
\begin{document}
\begin{questions}
\question \linktoanswer{For airborne sounds, the reference sound pressure taken to measure the sound pressure level is (\textbf{1991})}
\choice{$2\:X\:10^3\:N/m^2$}{$2\:X\:10^{-3}\:N/m^2$}{$2\:X\:10^5\:N/m^2$}{$2\:X\:10^{-5}\:N/m^2$}{d}
\question \linktoanswer{In a force-feed lubrication system adopted in the tractor engine, the type of pump generally used is}
\choice{Centrifugal pump}{Gear pump}{Rotary vane pump}{Plunger pump}{b}
\question \linktoanswer{The type of bearing used to support the disc on a standard disc plough is}
\choice{Bush bearing}{Plain roller bearing}{Tapered roller bearing}{Ball bearing}{c}
\end{questions}
%\newpage %Uncomment to put on new age
\newpage
Answer Key:
\bigskip
\showallanswers % Phil Hirschorn
\end{document}
