I'm trying to install some packages, including "ggplot2", "GEOquery", "limma", etc. Meanwhile, I keep facing either one of the errors mentioned below: (And the same errors with a different repository for "ggplot2" and "limma")
install.packages("GEOquery")
Warning in install.packages : unable to access index for repository https://bioconductor.org/packages/3.9/bioc/src/contrib: cannot open URL 'https://bioconductor.org/packages/3.9/bioc/src/contrib/PACKAGES'
Warning in install.packages : package ‘GEOquery’ is not available (for R version 3.6.0)