答案1
您可以尝试调整以下代码
\documentclass{article}
\usepackage{siunitx}
\usepackage{booktabs}
\usepackage{multirow}
\usepackage{lmodern}
\begin{document}
\begin{tabular}{ccccccccc}
\toprule
& & & \multicolumn{6}{c}{Number of droplets} \\
& \multirow{2}{*}{\begin{tabular}{c}Solvent $\Delta H_\text{vap}$ \\ \si{\kilo\joule\per\mol}\end{tabular}} & \multirow{2}{*}{\begin{tabular}{c}Volume of\\ the droplets (pl) \end{tabular}} & \multicolumn{6}{c}{Quantities (\si{ng})} \\
Drug & & & 1 & 10 & 50 & 100 & 250 & 500 \\
\cmidrule(lr){1-1}
\cmidrule(lr){2-2}
\cmidrule(lr){3-3}
\cmidrule(lr){4-9}
D1 & S1 & V1 & 1 & 8 & 40 & 81 & 202 & 403 \\
D2 & S2 & V2 & 1 & 9 & 43 & 86 & 216 & 431 \\
\bottomrule
\end{tabular}
\end{document}