Sql Server中的SUM显示错误

I am running below piece of code

我在代码下面运行

SELECT
    SUM(A.score),
    A.id,
    SUM(B.score)
FROM tableA A
INNER JOIN tableB B
    ON A.id = B.id
JOIN tableC C
    ON A.id = C.id
GROUP BY
    A.id
S