Table schema:
CREATE TABLE CAR_MAKERS (Id VARCHAR, Country VARCHAR); CREATE TABLE COUNTRIES (CountryId VARCHAR, CountryName VARCHAR); CREATE TABLE MODEL_LIST (Maker VARCHAR)

Question: How many car models are produced in the usa?
SQL: SELECT COUNT(*) FROM MODEL_LIST AS T1 JOIN CAR_MAKERS AS T2 ON T1.Maker = T2.Id JOIN COUNTRIES AS T3 ON T2.Country = T3.CountryId WHERE T3.CountryName = 'usa'