我无法打开Rcmdr包，弹出一些输出：
Loading required package: splines
Loading required package: RcmdrMisc
Loading required package: car
Loading required package: sandwich
Error: package or namespace load failed for 'RcmdrMisc' in loadNamespace(j <- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]):
there is no package called 'gridExtra'
Error: package 'RcmdrMisc' could not be loaded
我该怎么办？我对R没有任何了解。请帮助!!!!