01、写出下列单词的复数形式: 1.bus —— buses 2.box —— boxes 3.glass —— glasses 4.class —— classes 5.watch —— watches 6.mango —— mangoes 7.firefly —— fireflies 8.sheep —— sheep 9.people —— people 10.man —— men 11.woman —— women 12.apple —— apples 13.family —— families 14.library —— libraries 15.baby —— babies 16.boy —— boys 17.toy —— toys 18.child —— children