企业计划体系纵向可分为三个层次，即经营计划、（）和作业计划。
参考答案：业务计划
已知有理数a，b满足|a-1|+（b+2）2=0，则a+b的值=______．
汉译英：“品质检验证书；数量检验证书”，正确的翻译为：( )
A．Certificate of quality; Certificate of quantity
B．Certificate of quantity; Certificate of quality
C．Certificate of weight; Certificate of quality
D．Certificate of quality; Certificate of weight
