Table: pioneer
Columns: name
builder
type
works_number
built

Question: What is Name, when Builder is "Kerr Stuart"?
SQL: SELECT "name" FROM pioneer WHERE "builder" = 'kerr stuart'

Question: What is Built, when Works Number is "717"?
SQL: SELECT "built" FROM pioneer WHERE "works_number" = '717'

Question: What is Type, when Works Number is "unknown"?
SQL: SELECT "type" FROM pioneer WHERE "works_number" = 'unknown'