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....
She is wearing tight, black leggings and a baggy green jersey.她身穿黑色紧身裤和一件宽松的绿色针织套衫。Outstanding dairy Breeds include the Holstein, Guernsey, Jersey, Ayrshire, and Brown Swiss.优良的乳牛品种包括好斯敦牛 、 根西牛 、 泽西牛 、 亚尔夏牛和瑞士褐牛.They wer...