修改\course\format\ renderer.php，注释掉如下代码行：
// Display section bottom navigation.
$sectionbottomnav = '';
$sectionbottomnav .= html_writer::start_tag('div', array('class' => 'section-navigation mdl-bottom'));
$sectionbottomnav .= html_writer::tag('span', $sectionnavlinks['previous'], array('class' => 'mdl-left'));
$sectionbottomnav .= html_writer::tag('span', $sectionnavlinks['next'], array('class' => 'mdl-right'));
$sectionbottomnav .= html_writer::tag('div', $this->section_nav_selection($course, $sections, $displaysection),
array('class' => 'mdl-align'));
$sectionbottomnav .= html_writer::end_tag('div');
echo $sectionbottomnav;