改用openany而不是oneside。

高等微积分.tex

@@ -1,4 +1,4 @@
-\documentclass[12pt, UTF8, a4paper, fontset=none, oneside]{ctexbook}
+\documentclass[12pt, UTF8, a4paper, fontset=none, openany]{ctexbook}
 \usepackage{geometry}
 \usepackage{amsmath}
 \usepackage{amsthm}
@@ -15,6 +15,8 @@
 \ctexset{fontset=macnew}
 % \ctexset{fontset=windows} % On Windows
 
+\allowdisplaybreaks[4]
+
 \newtheorem{theorem}{定理}[section]
 \newtheorem{axiom}{公理}[section]
 \newtheorem{definition}{定义}[section]
@@ -22,7 +24,7 @@
 \newtheorem{corollary}{推论}[theorem]
 \newtheorem{example}{例}[section]
 \newtheorem{proposition}{命题}[theorem]
-\newtheorem*{remark}{Remark}
+\newtheorem*{remark}{注}
 
 % \renewcommand{\qedsymbol}{} %去掉证明结尾的方框
 \newcommand{\eqco}{\text{，}} % Chinese comma in equation