\documentclass[12pt]{article}

\usepackage[doublespacing]{setspace}
\usepackage{textcomp}
\usepackage{fancyhdr}%页眉页脚
\usepackage{lastpage}%获得总页码
\usepackage{amsfonts}%数学字符
\usepackage{amsmath}%美国数学会
\usepackage{amssymb}%黑板体和花体
\usepackage{makeidx}%索引
\usepackage{booktabs}
\usepackage[section]{placeins}%表格浮动
\usepackage{geometry}%页面格式
\usepackage{graphicx}%图片
\usepackage[square,sort,comma,numbers]{natbib}
\geometry{a4paper,left=2.4cm,right=2.4cm,top=2.4cm,bottom=2.4cm,centering}

\linespread{1} %行间距倍数

\pagestyle{fancy}
\lhead{Team \# 1903487}
\rhead{page \thepage{} of \pageref{LastPage}}

\begin{document}

\begin{abstract}
abstract
\end{abstract}

\begin{center}
Keywords
\end{center}
key words 

\newpage
\tableofcontents

\end{document}