—How old are you?
—I'm fifteen. I was born ______ 1990.[ ]
A. in
B. at
C. on
D. for
答案:A
The children put on ___ one-act play last Saturday.___ play amused everyone of us.
A.an…..An
B.a….An
C.an…The
D.a….The
某患者拔除左下第一磨牙残冠后第3天,出现发热38℃,张口受限,吞咽疼痛,检查见下颌升支后缘稍内侧轻度肿胀,深压痛,白细胞计数10.9×109/L,最可能原因是
A.干槽症
B.嚼肌间隙感染
C.颊间隙感染
D.翼颌间隙感染
E.颞下间隙感染