一、变化规则
1、一般情况下直接在词尾加s
例：book---books  apple---apples
      orange---_________        tiger---_________      girl---__________
banana---_________      lemon---__________          pencil---_________ 
2、以s,x,sh,ch结尾的单词，加es
例：bus---buses  box---boxes  fish---fishes  beach---beaches
class---          fox---        beach---          watch---     
3、以f或fe结尾的单词，把f或fe变成v加es
例：leaf---leaves
knife---      (刀)  wife---      （妻子）
4、以辅音字母加y结尾的单词，把y变i加es
例：fly---flies
      butterfly---_______  library---_______    baby---_____  puppy---______
二、选择单词的适当形式填空，写在横线上。
1. It’s so hot. I want to eat an ________. Do you like ______?( ice-cream, ice creams)
2.There are many_________(animal,animals) in the zoo.I like ________.( giraffe,giraffes)
3. ---Can I help you? ---Three _______ (doll, dolls),please.
library的复数4. I like____________( strawberry, strawberries) because they are sweet and juicy.
5. I don’t like _______(fly, flys,flies) because they are ugly and dirty(脏的).
6. Look at the_______(baby,babys,babies). They are so cute.
7. I like ________(water,waters) because we drink water everyday.
8. These _________(boy,boys,boies) like _________.( monkey,monkeys,monkeies)
9.Brush your________(tooth,teeth),Kitty. It’s time for bed.
三、有些单词就像孙悟空一样会变身，你知道他们是怎么变得吗？现在看看这些变身后的单词，你能把他变身以前的样子写出来吗？
  lions---_______    strawberries---________    roses---_________
teeth---_______    dragonflies---              pears---_________