常用复数名词
pants, glasses, socks, shoes, scissors
单数名词(结尾有-s，但是是单数名词)
news, lens, mathematics, politics, physics
单复数意义不同
good/goods, glass/glasses, cloth/clothes, wood/woods
数目字
two hundred people, three thousand students,
two dozen bottles of beer, a three-year-old child, in the 1960s
