用省略号书写并掌握其形状

Question

感谢论坛上某人的帮助，我终于可以在椭圆上写两个不同的字了。但是，现在我又遇到了椭圆形状的问题。椭圆的顶层总是只有一个单词，但在底层我有时必须一个接一个地写更多的单词，单词越多，椭圆就越像一个鸡蛋。有什么方法可以让 Latex 理解椭圆必须始终水平拉长吗？

\documentclass[a4paper,12pt]{article}
\usepackage[papersize={216mm,330mm},tmargin=20mm,bmargin=20mm,lmargin=20mm,rmargin=20mm]{geometry}
\usepackage{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{tikz}
\usetikzlibrary{positioning,shapes.multipart,shapes,fit}
\usepackage{hyperref}
\usepackage[fleqn]{amsmath}
\usepackage{array}
\usepackage{parskip}
\usepackage{float}

\renewcommand{\thesubsection}{\thesection.\alph{subsection}}
\setlength{\parindent}{0pt}


\tikzset{
    basic/.style={
        draw,
        rectangle split,
        rectangle split parts=2,
        rectangle split part fill={blue!20,white},
        text width=0.3\textwidth,
        align=center,
        font=\itshape
    },
    Ellipse/.style={
        ellipse, 
        draw, 
        shape aspect=2, 
        inner sep=5pt,
        text centered,
        fill=blue!10!white,
        font=\itshape
    },
    splitEllipse/.style={
        draw, 
        fill=blue!10!white,
        shape=ellipse split,
        align=center,
        minimum width=1cm,
        inner sep=5pt,
    }
}

\begin{document}
\begin{figure}[H]
    \centering
    \begin{tikzpicture}
    [every node/.style={scale=0.6}]
\node[Ellipse,](Association 1){Association 1};
 \node[splitEllipse, below= 0.5cm and 0.5cm of Association 1](Relation 7){Relation 7\\
        \nodepart{lower}
        A71 \\
        A72\\
        A73};
        \end{tikzpicture}
        \end{figure}
\end{document}