请选出每组单词中不同类的一个. ( ) 1. A. lion( )

( ) 2. A. fifth

( ) 3. A. heavy

( ) 4. A. funny

( ) 5. A. Sunday

B. second

B. clean

B. chicken

B. sweet

C. fresh

C. dirty

C. sandwich

C. Thursday

D. third

D. carefully

D. cheese

D. Tuesday