颌下腺深层延长部进入口内的部位在（）
A.下颌舌骨肌前缘
B.下颌舌骨肌后缘
C.颏舌肌内侧
D.颏舌肌外侧
E.下颌骨内侧
参考答案：B
连词成句。
1. park, an, never, I, amusement, been, to, have
2. and, take, Tina, going, the, subway, Linda, to, are
3 . you, start, English, did, when, learning
4. been, long, there, how, have, you
5. have, their, English, to, they, improve
试述蝶阀的特点？
