Because they have same convergence region, sum of series and combinational twin identifies was obtained using the method of substitution.

它们有相同的收敛区间，应用代入法求出它们的级数和，从而获得孪生组合恒等式。

youdao

Life is a series of collisions with the future; it is not the sum of what we have been, but what we yearn to be.

生活就是一系列与未来之间的碰撞；它不是我们过去曾经是什么的总和，而是我们将来想要成为什么的总和。

youdao

That’s why you don’t usually see a series of 99-cent charges on your credit card bill; they are processed as one lump sum.

通常你在信用卡账单上看不到一串串有不到1元零头的费用，就是这个原因，这些费用已经汇总计算了。

youdao

Many outsiders sum up "Frenchness" through a series of cliches berets, baguettes, good cheese and wine.

VOA: standard.2009.12.30

The purchase may be made outright (lump sum) or through a series of deferred (installment) payments.

FORBES: Working With Islamic Finance