Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE ship (TYPE VARCHAR, Tonnage INTEGER)
### Question:
Show the types of ships that have both ships with tonnage larger than 6000 and ships with tonnage smaller than 4000.
### Answer:
SELECT TYPE FROM ship WHERE Tonnage > 6000 INTERSECT SELECT TYPE FROM ship WHERE Tonnage < 4000