塑料成型工艺特性有（）。
A.收缩性
B.流动性
C.结晶性
D.吸湿性
E.热敏性
F.应力开裂
参考答案：A, B, C, D, E, F
They don't have to their school uniforms. [ ]
A. dress
B. have on
C. put on
D. wear
难产损伤引起的尿瘘手术修补时间应为（）
A.立即修补
B.3～6个月后修补
C.1～3个月后修补
D.6～12个月时修补
E.12个月以后修补
