Table: academ
Columns: name
year_began
registration
userpics_free
userpics_paid
monthly_cost_for_paid_account
yearly_cost_for_paid_account
permanent_account

Question: Which permanent account has registration of invite-only and userpics free of unknown?
SQL: SELECT "permanent_account" FROM academ WHERE "userpics_free" = 'unknown' AND "registration" = 'invite-only'

Question: What is the year began for the site with free userpics cost of $1 and a userpics paid value of N/A?
SQL: SELECT "year_began" FROM academ WHERE "userpics_paid" = 'n/a' AND "userpics_free" = '1'