提示如下：
试开URL’https://mirrors.tuna.tsinghua.ed ... copula_0.999-13.zip
Error in download.file(url, destfile, method, mode = "wb", ...) :
  无法打开URL'https://mirrors.tuna.tsinghua.edu.cn/CRAN/bin/windows/contrib/3.2/copula_0.999-13.zip'
此外: Warning message:
In download.file(url, destfile, method, mode = "wb", ...) :
  InternetOpenUrl失败:’操作超时'
Warning in download.packages(pkgs, destdir = tmpd, available = available,  :
  下载程序包‘copula’时出了问题

请大牛们赐教！