口呼吸会出现的错牙合 （）
A.牙弓变宽
B.腭盖降低
C.前牙反牙合
D.前牙拥挤
E.以上都不是
参考答案：D
The two categories of meaning of language proposed by Wilkins are（）.
A. notions and functions
B. notions and forms
C. forms and functions
D. general and specific
干燥收缩率
