\begin{tabular}{ p{2.2cm}p{2.2cm}p{2.2cm}p{7cm} }
\hline
\multicolumn{1}{c}{\bfseries Approach} & \multicolumn{1}{c}{\bfseries Technique Used} & \multicolumn{1}{c}{\bfseries Premise considered} & \multicolumn{1}{c}{\bfseries Attributes} \\ \hline
\multirow{2}{*}{Virtual forces} & Potential Fields [16] & Location information and range & Balanced deployment with the help of repulsive mechanism, when in proximity to obstacles. \\ \cline{2-4}
& DSS Algorithm [17] & Location information & A profitable scheme to conserve energy during deployment of a WSN divided into clusters. \\
\hline
\multirow{2}{*}{Computational Geometry} & Co-Fi [18] & Location information & Distributed scheme to conserve energy and provide regulated coverage fidelity. \\ \cline{2-4}
& VEC, VOR, Minmax [19] & Location information & Identify coverage holes and enabling sensors to move away from dense area. \\
\hline
\end{tabular}
答案1
现在没有时间解释。
\documentclass{article}
\usepackage{multirow,array}
\usepackage{showframe} %%% just for demo Remove
\begin{document}
\noindent
\begin{tabular}{*{3}{>{\raggedright\arraybackslash}p{0.2\textwidth}}%
>{\raggedright\arraybackslash}p{\dimexpr0.4\textwidth-8\tabcolsep\relax} }
\hline
\bfseries Approach & \bfseries Technique Used & \bfseries Premise considered & \bfseries Attributes \\ \hline
\multirow{2}{*}[-6em]{Virtual forces} & Potential Fields [16] & Location information and range & Balanced deployment with the help of repulsive mechanism, when in proximity to obstacles. \\ \cline{2-4}
& DSS Algorithm [17] & Location information & A profitable scheme to conserve energy during deployment of a WSN divided into clusters. \\
\hline
\multirow{2}{0.2\textwidth}[-4.5em]{Computational Geometry} & Co-Fi [18] & Location information & Distributed scheme to conserve energy and provide regulated coverage fidelity. \\ \cline{2-4}
& VEC, VOR, Minmax [19] & Location information & Identify coverage holes and enabling sensors to move away from dense area. \\
\hline
\end{tabular}
\end{document}
