We should not cuttrees.
A. off B. upC. down
The weather is gettingin August.
A. more hot B. hoterC. hotter
Trees can keepcool.
A. usB. weC. our
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