We're in class. You'd better not _______. [ ]
A. talk
B. talking
C. talked
D. to talk
答案:A
在△ABC中,∠A=55°,∠C=42°,则∠B的度数为[ ]
A.42°
B.55°
C.83°
D.97°
氯氮革为
A.麻醉性镇痛药
B.镇静催眠药
C.局部麻醉药
D.全身麻醉药
E.抗精神失常药