当我保存此表单时，每次保存时，它都会生成新文件（即要求保存新的 .pdf），我们是否可以更新单个 pdf 中的所有保存。
\documentclass[12pt,a4paper,landscape]{article}
\usepackage[left=0.75in,right=0.75in,top=0.5in,bottom=0.5in]{geometry}
\usepackage{array}
\usepackage{multirow}
\usepackage{marvosym}
\usepackage{graphicx}
\usepackage{xcolor}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{url}
\urlstyle{rm}
\usepackage{array}
\usepackage{spreadtab}
\usepackage{hyperref}
\begin{document}
\begin{Form}
\begin{center}
%\includegraphics[scale=0.3]{VITLogoNew}\\ [8pt]
\textbf{School of Mechanical and Building Sciences} \\ [4pt]
\textbf{M.Tech, Structural Engineering} \\ [4pt]
\textbf{Fall 2017 -- RBL - I Review}
\end{center}
\vskip 0.5cm
\begin{flushleft}
\textbf{Name of the Reviewer:-}
\ChoiceMenu[print,height=0.5cm,width=10.5cm,format = {textFont = 'Times New Roman'},combo,default=,name=Name of the Reviewer]{}{Faculty 1, Faculty 2, Faculty 3} \\ [8pt]
\textbf{Date of Review:-} $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ \\ [8pt]
\end{flushleft}
\begin{center}
\def\arraystretch{1.5}{
\begin{tabular}{|>{\centering\arraybackslash}p{1.0cm}|p{4.8cm}|p{7.3cm}|>{\centering\arraybackslash}p{2.5cm}|>{\centering\arraybackslash}p{2.5cm}|>{\centering\arraybackslash}p{2.5cm}|>{\centering\arraybackslash}p{2.5cm}|} \cline{4-7}
\multicolumn{3}{c|}{} & \multicolumn{2}{|c|}{\textbf{Group \#1}} & \multicolumn{2}{|c|}{\textbf{Group \#2}} \\ \cline{4-7}
\multicolumn{3}{c|}{} & \textbf{Student 1} & \textbf{Student 2} & \textbf{Student 1} & \textbf{Student 2} \\ \hline
\textbf{S.No.} & \multicolumn{1}{c|}{\textbf{Criteria}} & \multicolumn{1}{c|}{\textbf{Sub-Criteria}} & \ChoiceMenu[print,height=0.2cm,width=2.4cm,combo,default=,name=group1name1]{}{17MST1001 , 17MST1002 , 17MST1003 , 17MST1004 , 17MST1005 , 17MST1006 , 17MST1008, 17MST1009, 17MST1010, 17MST1011, 17MST1012, 17MST1013, 17MST1014, 17MST1015, 17MST1017, 17MST1018, 17MST1019, 17MST1020, 17MST1021, 17MST1022, 17MST1023, 17MST1024, 17MST1025, 17MST1026, 17MST1027, 17MST1028, 17MST1029, 17MST1030, 17MST1031, 17MST1032, 17MST1033, 17MST1034, 17MST1035, 17MST1036, 17MST1037, 17MST1038, 17MST1039, 17MST1040, 17MST1041, 17MST1042, 17MST1043, 17MST1044, 17MST1045, 17MST1046, 17MST1047, 17MST1048, 17MST1049, 17MST1050, 17MST1051, 17MST1052, 17MST1053, 17MST1054} & \ChoiceMenu[print,height=0.2cm,width=2.4cm,combo,default=,name=group1name2]{}{17MST1001 , 17MST1002 , 17MST1003 , 17MST1004 , 17MST1005 , 17MST1006 , 17MST1008, 17MST1009, 17MST1010, 17MST1011, 17MST1012, 17MST1013, 17MST1014, 17MST1015, 17MST1017, 17MST1018, 17MST1019, 17MST1020, 17MST1021, 17MST1022, 17MST1023, 17MST1024, 17MST1025, 17MST1026, 17MST1027, 17MST1028, 17MST1029, 17MST1030, 17MST1031, 17MST1032, 17MST1033, 17MST1034, 17MST1035, 17MST1036, 17MST1037, 17MST1038, 17MST1039, 17MST1040, 17MST1041, 17MST1042, 17MST1043, 17MST1044, 17MST1045, 17MST1046, 17MST1047, 17MST1048, 17MST1049, 17MST1050, 17MST1051, 17MST1052, 17MST1053, 17MST1054} & \ChoiceMenu[print,height=0.2cm,width=2.4cm,combo,default=,name=group2name1]{}{17MST1001 , 17MST1002 , 17MST1003 , 17MST1004 , 17MST1005 , 17MST1006 , 17MST1008, 17MST1009, 17MST1010, 17MST1011, 17MST1012, 17MST1013, 17MST1014, 17MST1015, 17MST1017, 17MST1018, 17MST1019, 17MST1020, 17MST1021, 17MST1022, 17MST1023, 17MST1024, 17MST1025, 17MST1026, 17MST1027, 17MST1028, 17MST1029, 17MST1030, 17MST1031, 17MST1032, 17MST1033, 17MST1034, 17MST1035, 17MST1036, 17MST1037, 17MST1038, 17MST1039, 17MST1040, 17MST1041, 17MST1042, 17MST1043, 17MST1044, 17MST1045, 17MST1046, 17MST1047, 17MST1048, 17MST1049, 17MST1050, 17MST1051, 17MST1052, 17MST1053, 17MST1054} & \ChoiceMenu[print,height=0.2cm,width=2.4cm,combo,default=,name=group2name2]{}{17MST1001 , 17MST1002 , 17MST1003 , 17MST1004 , 17MST1005 , 17MST1006 , 17MST1008, 17MST1009, 17MST1010, 17MST1011, 17MST1012, 17MST1013, 17MST1014, 17MST1015, 17MST1017, 17MST1018, 17MST1019, 17MST1020, 17MST1021, 17MST1022, 17MST1023, 17MST1024, 17MST1025, 17MST1026, 17MST1027, 17MST1028, 17MST1029, 17MST1030, 17MST1031, 17MST1032, 17MST1033, 17MST1034, 17MST1035, 17MST1036, 17MST1037, 17MST1038, 17MST1039, 17MST1040, 17MST1041, 17MST1042, 17MST1043, 17MST1044, 17MST1045, 17MST1046, 17MST1047, 17MST1048, 17MST1049, 17MST1050, 17MST1051, 17MST1052, 17MST1053, 17MST1054} \\ \hline
1. & \multirow{2}{*}{Presentation (30\%)} & Oral Presentation Skill (15\%) & \ChoiceMenu[print,height=0.2cm,width=1.5cm,combo,default=,name=box1]{}{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10} & & & \\ \cline{1-1} \cline{3-7}
2. & & Visual Aid used (15\%) & \ChoiceMenu[print,height=0.2cm,width=1.5cm,combo,default=,name=box2]{}{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10} & & & \\ \hline
3. & \multirow{2}{*}{Work Accomplished (40\%)} & Quality of Work Done (20\%) & \ChoiceMenu[print,height=0.2cm,width=1.5cm,combo,default=,name=box3]{}{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10} & & & \\ \cline{1-1} \cline{3-7}
4. & & Completion of Work (20\%) & \ChoiceMenu[print,height=0.2cm,width=1.5cm,combo,default=,name=box4]{}{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10} & & & \\ \hline
5. & \multicolumn{2}{l|}{Asnwering the Queries (10\%)} & \ChoiceMenu[print,height=0.2cm,width=1.5cm,combo,default=,name=box5]{}{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10} & & & \\ \hline
6. & \multirow{2}{*}{Documentation (20\%)} & Content of the Report (10\%) & \ChoiceMenu[print,height=0.2cm,width=1.5cm,combo,default=,name=box6]{}{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10} & & & \\ \cline{1-1} \cline{3-7}
7. & & Report Preparation (Formatting) (10\%) & \ChoiceMenu[print,height=0.2cm,width=1.5cm,combo,default=,name=box7]{}{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10} & & & \\ \hline
& \multicolumn{2}{r|}{\textbf{Grand Total} (Out of 70)} & & & & \\ \hline
& \multicolumn{2}{r|}{\textbf{Percentage}} & & & & \\ \hline
\end{tabular}}
\begin{flushright}
\vskip 1.5cm
\textbf{Signature of the Reviewer}
\end{flushright}
\end{center}
\end{Form}
\end{document}