There are several ways to separate excited from unexcited molecules, thus harvesting the desired isotope.目前有几种方法可以把受激发分子同未受激发分子分离开, 这样,就可以大量得到我们所需要的同位素了.He was still unexcited.他仍然不激动....
Fat is an excellent insulator against the cold.脂肪是极好的抵御寒冷的绝热体。Dry air is a good insulator, but sea water is not.干燥空气是一种好绝缘物, 海水则不是.The atoms of an insulator hold their electrons very tight.绝缘体的原子把电子抓得很牢....