But for practical purposes, there is no difference.

但就实际用途而言，没什么区别。

And they are now worn by both men and women for practical purposes rather than for decoration.

现在男女佩戴它们是出于实用目的，而不是装饰。

" Technology" is using science for practical purposes or using scientific principles to create machines and other instruments.

“技术”是将科学用于实用目的或使用科学原理来制造机器和其他仪器。

The seeming, and for practical purposes, repulsion of so-called positive and negative matter will be explained in another session, as if I begin to develop upon this now, you will end up with a longer session, not a short one.

所谓的正负物质的看似，以及有其实际目的排斥力，将在另一次课上解释。因为如果我现在就开始展开这题目，你们最后就会有一节更长的课，而不是短课。