建筑施工企业生产经营必备证件应有（）
A.安全许可证
B.安全文明工地证书
C.优质工程证书
参考答案：A
简述布鲁纳认知-结构学习论的主要观点。
Which of the following is NOT a form of wage erosion
How long is the duration of the typical severance package
A．19 years.B．5 months.C．10 months.D．2 months and a half.
