在下述黏膜组织中，何处无黏膜下层（）
A.颊
B.唇
C.舌腹
D.口底
E.龈
参考答案：E
I heard that we must have _________ teaching building __________ .
A．another , to be built
B．the other , to build
C．a third , built
D．the other , built
正常人体不出现的叩诊音是
A．清音B．浊音C．实音D．鼓音E．过清音
