Mr.Liu and his wife are looking at ____.
查看答案
The dog is running ____ the grass.
A. across
B. cross
C. crosses
There is an electric ____ in the kitchen.
A. cook
B. cooker
C. cookers
A ____ is sweeping the floor.
A. cleaning
B. clean
C. cleaner
He is cleaning his ____.
A. teeth
B. tooth
C. tooths