未定义的控制序列 \textb

Question

我使用以下代码来创建新页面，并将新页面中开始的主题加粗。

\newpage{\textb{Appendix B}}

但我不知道为什么会出现以下错误：

! Undefined control sequence.

 l.322 \newpage{\textb
                     {Appendix B}}

The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

File: images/image.png Graphic file (type png)
<use images/image.png>
Package pdftex.def Info: images/groningen.png  used on input line 395. on input
 line 395.
Package pdftex.def Info: Requested size: 56.9055pt x 18.8136pt on input line 39
5.

有人能告诉我如何修复它吗？我想删除这个错误。我尝试了不同的解决方案，但上面的代码有什么问题？我想在新页面中以粗体格式显示附录。有什么建议吗？