带有覆盖的 itemize 环境内的 beamer 块

Question

我有一个像这样的框架，在 itemize 环境里面有一个块，还有一个覆盖：

\begin{frame}   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  \frametitle{Comparing two Gaussian means: equality}

\begin{itemize}

\item<1-> Assume for instance that each measurement is $\approx 1000$ 

\item<1-> Would you mind if $\mu_1=1000$ and $\mu_2=1000.1$ ?

\item<1->[] 
\begin{alertblock}{Significant difference does not mean important difference}
  "The mean of the Gaussian distribution is well estimated whenever $n \geq 30$ 
  "Significant difference" is a shortcut for \emph{significantly different from $0$}. 
  The presence of a significant difference shows that there is a strong evidence that 
  $\boxed{\mu_1 \neq \mu_2}$ 
\end{alertblock}

\vspace{-13pt}
\item<1->[] 
\begin{columns}[T]
\column{.5\linewidth}
\begin{itemize}
\item<1-> Whether $\mu_1=\mu_2$ or  $\mu_1 \neq \mu_2$  is \emph{not} the question of interest
\item<2-> xx
\end{itemize}
\column{.5\linewidth}
\only<2->{\begin{figure}
...
\end{figure}
}
\end{columns}
\end{itemize}

\end{frame}

您可以看到此处的渲染问题在于两张幻灯片没有很好地重叠，我尝试了很多次都没有成功。

Answer 1

这正是区域环境的目的overlay；在我的示例中，我在底部使用了一个虚拟图像：

\documentclass{beamer}
\usetheme{Boadilla}
\begin{document}

\begin{frame}   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\frametitle{Comparing two Gaussian means: equality}

\begin{overlayarea}{\textwidth}{\textheight}
\begin{itemize}
\item<1-> Assume for instance that each measurement is $\approx 1000$ 
\item<1-> Would you mind if $\mu_1=1000$ and $\mu_2=1000.1$ ?
\item<1->[] 
\begin{alertblock}{Significant difference does not mean important difference}
  "The mean of the Gaussian distribution is well estimated whenever $n \geq 30$ 
  "Significant difference" is a shortcut for \emph{significantly different from $0$}. 
  The presence of a significant difference shows that there is a strong evidence that 
  $\boxed{\mu_1 \neq \mu_2}$ 
\end{alertblock}
\vspace{-13pt}
\item<1->[] 
\begin{columns}[T]
\column{.5\linewidth}
\begin{itemize}
\item<1-> Whether $\mu_1=\mu_2$ or  $\mu_1 \neq \mu_2$  is \emph{not} the question of interest
\item<2-> xx
\end{itemize}
\column{.5\linewidth}
\only<2->{\begin{figure}
\includegraphics[height=2cm]{example-image-a}
\end{figure}
}
\end{columns}
\end{itemize}
\end{overlayarea}
\end{frame}

\end{document}