Thanks your reply for my problem.
The errors are below:
install.packages("tidyverse", lib = "/usr/lib/R/library")
Warning in install.packages :
'lib = "/usr/lib/R/library"' is not writable
Would you like to use a personal library instead? (yes/No/cancel) no
Error in install.packages : unable to install packages
.libPaths()
[1] "/home/rstudio-user/R/x86_64-pc-linux-gnu-library/3.6"
[2] "/opt/R/3.6.0/lib/R/library"
install.packages("tidyverse", lib = "/opt/R/3.6.0/lib/R/library")
Warning in install.packages :
'lib = "/opt/R/3.6.0/lib/R/library"' is not writable
Would you like to use a personal library instead? (yes/No/cancel)
So I think this problem about permission. but packages from CRAN by use install.packages() and from Bioconductor by use BiocManager::install(), it always be installed to /home/rstudio-user/R. and the space is only 2.7G. I want to know that others rstudio cloud project is same as mine. and thank you for time and reply.