在下面的代码中，至少第一个命令\vspace{3pt plus 1pt minus 0pt}被忽略了。我希望 I.) 和 II.) 中的语句排版在问题下方。
\documentclass{amsart}
\usepackage{amsmath}
\begin{document}
\noindent \textbf{1.) }$x_{1}$, $x_{2}$, \ldots{} $x_{n}$ are consecutive, positive integers. Is the sum of them odd? \vspace{3pt plus 1pt minus 0pt}
\noindent \hphantom{\textbf{1.) }}\hspace{3em}
\begin{tabular}{r@{}l}
\textbf{I.) } & The average of the given integers is odd. \\
\textbf{II.) } & \textit{n} is odd.
\end{tabular}
\vspace{3pt plus 1pt minus 0pt}
\begin{tabbing}
\hspace*{2em} \= \kill
\> a.) Statement I.) alone is sufficient, but statement II.) is not sufficient. \\
\> b.) Statement I.) alone is not sufficient, but statement II.) is sufficient. \\
\> c.) Both statements together are sufficient, but neither statement alone is sufficient. \\
\> d.) Each statement alone is sufficient. \\
\> e.) Statements I.) and II.) together are not sufficient.
\end{tabbing}
\end{document}
答案1
如果您使用\vspace水平模式（您的两个示例都是这种情况），那么在段落被拆分成行之后，将在与添加 vspace 的位置相对应的行之后添加空格。在您的示例中，行恰好在之后拆分，odd?因此在该位置添加了 3pt。
但是我不会在文档主体中使用任何明确的间距，我会使用更像这样的标记：
\documentclass{amsart}
\usepackage{amsmath}
\usepackage{enumitem}
\begin{document}
\begin{enumerate}[label=\textbf{\arabic*.)}]
\item $x_{1}$, $x_{2}$, \ldots{} $x_{n}$ are consecutive, positive integers. Is the sum of them odd?
\begin{enumerate}[label=\textbf{\Roman*.)}]
\item The average of the given integers is odd.
\item $n$ is odd.
\end{enumerate}
\begin{enumerate}[label=\alph*.),topsep=\baselineskip]
\item Statement I.) alone is sufficient, but statement II.) is not sufficient.
\item Statement I.) alone is not sufficient, but statement II.) is sufficient.
\item Both statements together are sufficient, but neither statement alone is sufficient.
\item Each statement alone is sufficient.
\item Statements I.) and II.) together are not sufficient.
\end{enumerate}
\end{enumerate}
\end{document}