火眼金睛，选出不同类的单词。
( ) 1. A. teacher
( ) 2. A. her
( ) 3. A. five
( ) 4. A. eraser
( ) 5. A. yellow
( ) 6. A. under
( ) 7. A. knee
( ) 8. A. hair
( ) 9. A. he
( ) 10. A. happyB. desk
B. his
B. marker
B. pen
B. mouth
B. school
B. cool
B. black
B. she
B. son C. chair
C. book
C. four
C. open
C. blue
C. on
C. warm
C. red
C. long
C. father