为什么我的目录在docx编织中是空白的？

Question

我正在Rmarkdown做我的论文，我遇到了以下问题：

---
title: "Title"
author: "Me"
date: "May 20, 2018"
bibliography: bibliography.bib
output:
  word_document:
    toc: yes
    # theme: united
    # reference_docx: ref.docx
  html_document:
    # toc: true
    df_print: paged
  pdf_document: default
---

我的目录没有生成。

以外我没有收到任何警告

Output created: pdfrmd.docx
Warning message:
In hook_plot(x[i], reduce_plot_opts(options)) :
  Chunk options fig.align, out.width, out.height, out.extra are not supported for Word output