我有一个无法解决的问题。当我生成 PDF 文档并想将文本复制到终端或 WORD 文档时，下划线不会被复制。在 PDF 中，它确实会打印下划线（Adobe Acrobat Reader、Foxit Reader），但当我想将其从 PDF 复制到另一个位置时，会出现一个空白处。我使用_，我也尝试过\textunderscore。此外，我还使用和。（我看到它已通过 解决，\usepackage[utf8]{inputenc}但对我来说不起作用。）你能帮帮我吗？\usepackage[T1]{fontenc}\usepackage{lmodern}\usepackage[T1]{fontenc}
这是我的序言：
\documentclass[letterpaper]{article}
\usepackage[spanish]{babel}
\usepackage[utf8]{inputenc}
\usepackage{fancyhdr}
\usepackage{authblk}
\usepackage{amsfonts}
\usepackage[version=3]{mhchem}
\usepackage{textgreek}
\usepackage{pdflscape} % landscape pages
\usepackage[T1]{fontenc}
\usepackage{lmodern} % Previene advertencias sobre fuentes no disponibles
\usepackage{graphicx}
\usepackage[left=3cm,right=2cm,top=2cm,bottom=3cm]{geometry} % Configura los márgenes de página
%\usepackage{lineno} %Numeros en las lineas
%\linenumbers
%Paquete para incluir hipervínculos
\usepackage[colorlinks=true,
linkcolor = black,
urlcolor = blue,
citecolor = black,
anchorcolor = blue]{hyperref}
\usepackage{lipsum}
\usepackage{Sweave}
\usepackage{multirow}
\usepackage[table,xcdraw]{xcolor}
\usepackage{array}
\usepackage{tabu}
\usepackage[labelfont=bf]{caption} %Configura los titulos de las figuras y las tablas en negrita.
\usepackage{datetime}
\setlength{\parindent}{0pt}
%Paquete para el manejo de las unidades en el Sistema Internacional
\usepackage{siunitx}
\sisetup{mode=text, output-decimal-marker = {,}, per-mode = symbol, qualifier-mode = phrase, qualifier-phrase = { de }, list-units = brackets, range-units = brackets, range-phrase = --}
\DeclareSIUnit[number-unit-product = \;] \atmosphere{atm}
\DeclareSIUnit[number-unit-product = \;] \pound{lb}
\DeclareSIUnit[number-unit-product = \;] \inch{"}
\DeclareSIUnit[number-unit-product = \;] \foot{ft}
\DeclareSIUnit[number-unit-product = \;] \yard{yd}
\DeclareSIUnit[number-unit-product = \;] \mile{mi}
\DeclareSIUnit[number-unit-product = \;] \pint{pt}
\DeclareSIUnit[number-unit-product = \;] \quart{qt}
\DeclareSIUnit[number-unit-product = \;] \flounce{fl-oz}
\DeclareSIUnit[number-unit-product = \;] \ounce{oz}
\DeclareSIUnit[number-unit-product = \;] \degreeFahrenheit{\SIUnitSymbolDegree F}
\DeclareSIUnit[number-unit-product = \;] \degreeRankine{\SIUnitSymbolDegree R}
\DeclareSIUnit[number-unit-product = \;] \usgallon{galón}
\DeclareSIUnit[number-unit-product = \;] \uma{uma}
\DeclareSIUnit[number-unit-product = \;] \ppm{ppm}
\DeclareSIUnit[number-unit-product = \;] \eqg{eq-g}
\DeclareSIUnit[number-unit-product = \;] \normal{\eqg\per\liter\of{solución}}
\DeclareSIUnit[number-unit-product = \;] \molal{\mole\per\kilo\gram\of{solvente}}
\addto\captionsspanish{\renewcommand{\tablename}{Tabla}} %Cambia el nombre de cuadros a
%tablas