people是一个集合名词,是复数,跟我们常说的那些特殊变化的名词不一样.
变成复数需要特殊变化的单词如下：
wife---wives
knife---knives
leaf---leaves
wolf---wolves
Negro---Negroes
hero---heroes
tomato---tomatoes
potato--- potatoes
foot---feet
goose---geese
tooth---teeth
child---children
man---men
woman---women
mouse---mice
sheep---sheep
deer---deer
fish---fish
datum---data
medium---media
bacterium---bacteria
curriculum---curricula
criterion---criteria
phenomenon---phenomena
analysis---analyses
basis---bases
crisis---crises
diagnosis---diagnoses