刚刚学习R，CRAN镜像连接不上

问题遇到的现象和发生背景

今天刚刚学习R，CRAN镜像连接不上

问题相关代码，请勿粘贴截图

chooseCRANmirror()
Warning: failed to download mirrors file (无法打开URL'https://cran.r-project.org/CRAN_mirrors.csv'); using local file 'C:/PROGRA~1/R/R-4.0.4/doc/CRAN_mirrors.csv'
Warning message:
In download.file(url, destfile = f, quiet = TRUE) :
InternetOpenUrl失败:’无法与服务器建立连接'

运行结果及报错内容

chooseCRANmirror()
Warning: failed to download mirrors file (无法打开URL'https://cran.r-project.org/CRAN_mirrors.csv'); using local file 'C:/PROGRA~1/R/R-4.0.4/doc/CRAN_mirrors.csv'
Warning message:
In download.file(url, destfile = f, quiet = TRUE) :
InternetOpenUrl失败:’无法与服务器建立连接'