sum n.总数[计, 额];【数】和[the sum]概略, 要点金额, 款项算术(题), 运算[诗]绝顶, 顶点, 极点the sum of this book 这本书的要点a good sum 可观的金额be good at sums 长于算术The sum of 5 and 4 is 9....