下列哪些情况禁止使用链条葫芦（）
A.吊钩有变形时
B.链轮有变形时
C.被吊物形状不规则
D.链条直径磨损量达10%时
参考答案：A, B, D
有慢性便秘的患者发生剧烈腹痛应考虑
A．"铅管"征B．"鹅卵石"征C．"鸟嘴"征D．"杯口"征E．充盈缺损
I hear one of my classmates America since 1980. [ ]
A. are from
B. have gone to
C. has lived in
