找出下列不同类的单词，将其编号写在前面的括号里。
( )（1）A. housework B. homework C. apple
( )（2）A.sad B. monkey C. upset
( )（3）A. bring B. myself C. yourself
( )（4）A.rat B. rabbit C. cars
( )（5）A. apple B. lunch C. supper
We need more trees.
A. plantB. to plantC. planting
听音，选出你所听到的单词。
（）（1）A . cleanB. cool C. keep D. car
（）（2）A . hot B. hotter C. get D. getting
（）（3）A .buildingB. changing C. singing D. interesting
（）（4）A .plant B. down C. becomeD. long
（）（5）A .spring B. air C. freshD. rice
Planting treesgood for us.
A. am B. isC. are
Trees can keep the air.
A. clean B. beautiful C. hot
I should my little sister.
A. take careB. look like
C. look after