Table: t_2001_paleontology
Columns: name
status
authors
unit
location
notes

Question: What unit is in Mongolia?
SQL: SELECT "unit" FROM t_2001_paleontology WHERE "location" = 'mongolia'

Question: What unit is in Argentina?
SQL: SELECT "unit" FROM t_2001_paleontology WHERE "location" = 'argentina'

Question: What name is located in China?
SQL: SELECT "name" FROM t_2001_paleontology WHERE "location" = 'china'

Question: What unit is located in China and has Zhou Zhang as an author?
SQL: SELECT "unit" FROM t_2001_paleontology WHERE "location" = 'china' AND "authors" = 'zhou zhang'