四环素类的不良反应可以对骨及牙齿的影响
A. 对
B. 错
What is the plural noun for more than one tooth?
A. tooths
B. toothes
C. teeth
D. teeths
Which word has an irregular plural form?
A. child
B. foot
C. goose
D. all of the above
We have one sheep but what do we say if there are more than one?
A. sheep
B. sheeps
C. sheeplings
D. sheepies