答案1
使用verse
包和altverse
格式化环境。
% parastylesprob.tex SE 598663
\documentclass{book}
\usepackage{verse}
\newcommand{\textlines}{This is just a couple of lines of text so that one can
see the the textwidth of this document, and help visualize where the midpoint is.}
\newcommand{\verseline}{This is a line of verse}
\settowidth{\versewidth}{\verseline}
\begin{document}
\textlines
\begin{verse}[\versewidth]
\begin{altverse}
\verseline \\
\verseline \\
\verseline \\
\verseline
\end{altverse}
\begin{altverse}
\verseline \\
\verseline \\
\verseline \\
\verseline
\end{altverse}
\end{verse}
\textlines
\end{document}