表定义为:
CREATE TABLE "expense"
(
expense_id TEXT
constraint expense_pk
primary key,
expense_description TEXT,
expense_date TEXT,
cost REAL,
approved TEXT,
link_to_member TEXT
constraint expense_member_member_id_fk
references member,
link_to_budget TEXT
constraint expense_budget_budget_id_fk
references budget
)
问题如下:List the expenses that spend more than fifty dollars on average.. 请使用SQL回答。
额外参考信息为:expense refers to expense_description; spend more than fifty dollars on average refers to AVG(cost) > 50  There should be exactly 2 paragraphs separated by the markdown divider: ***.
user