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 table_name_18 (first_elected INTEGER, district VARCHAR, committee VARCHAR)
### Question:
What is the average first elected year that has a district of 11 and a committee of environmental matters?
### Answer:
SELECT AVG(first_elected) FROM table_name_18 WHERE district = "11" AND committee = "environmental matters"