Bill is in the classroom, doing _______ homework. [ ]
A. he
B. him
C. his
D. himself
答案:C
可因下齿槽神经麻醉导致医源性感染的间隙为()
A.眶下间隙
B.翼下颌间隙
C.咬肌间隙
D.下颌下间隙
E.颞间隙感染
小儿肺炎时室内相对湿度宜保持在:
A.40%B.50%C.60%D.70%E.80%