"psql -At -F" export column from table to .csv

Hi ,

I think you maybe familiar with this command:
psql -At -F "," -c "select ..." > query.csv

My question is:
is it possible to export several different columns from different
tables into the same .csv file; something like:  psql -At -F "," -c
"select ..." "select ..." "select ..." "select ..." > query.csv

Then, how to write the command in the correct way?

Thanks!

Nina