A、<p><span style=\""font-family: 微软雅黑, 'Microsoft YaHei';\"">高阶无穷小<\/span><br><\/p>
B、<p><span style=\""font-size:14px;font-family:'微软雅黑','sans-serif'\"">同阶无穷小，但不等价<\/span><\/p>
C、<p><span style=\""font-family: 微软雅黑, 'Microsoft YaHei';\"">低阶无穷小<\/span><br><\/p>
D、<p><span style=\""font-family: 微软雅黑, 'Microsoft YaHei';\"">等价无穷小<\/span><br><\/p>