Translate the following question to SQL: What are the heights of body builders with total score smaller than 315?

Schema: CREATE TABLE body_builder (
    Body_Builder_ID INT   PRIMARY KEY,
    People_ID INT,
    Snatch REAL,
    Clean_Jerk REAL,
    Total REAL,
    UNIQUE (Body_Builder_ID),
    FOREIGN KEY (People_ID) REFERENCES people(People_ID)
);

CREATE TABLE people (
    People_ID INT   PRIMARY KEY,
    Name TEXT,
    Height REAL,
    Weight REAL,
    Birth_Date TEXT,
    Birth_Place TEXT,
    UNIQUE (People_ID)
);
user
SELECT T2.Height FROM body_builder AS T1 JOIN people AS T2 ON T1.People_ID  =  T2.People_ID WHERE T1.Total  <  315
assistant