在某些情况下，您必须考虑加或减的小时数；在其他情况下，无需进行调整。

In some cases, you must account for the hour added or subtracted; in other cases no adjustment is needed.

youdao

数量：除非另作安排，数量可能由卖方选择作加或减5%的变动。

Quantity: Quantity, unless otherwise arranged, shall be subject to a variation of 5% plus or minus at Sellers' option.

youdao

在这些脉冲进入光纤后，不同颜色光之间可以加或减，混合在一起，创造出总数达350种不同颜色的光。每一种光都可以被编码成自己的数据流。

When these pulses are sent into an optical fibre, the different colours can mix together and create 325 different colours in total, each of which can be encoded with its own data stream.

youdao

This is the plus or minus, so the product of the uncertainty and the momentum.

是加或减，所以不确定度和动量的结果。

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