由实际光线汇聚而成的像叫____像；由实际光线的反向延长线相交而成的像叫____像，它____用光屏承接．
实；虚；不能
绩效考核指标筛选的依据是：（）
A.企业发展规划和企业竞争情况
B.企业竞争情况和企业最薄弱环节
C.企业发展规划和企业最薄弱环节
D.企业发展规划和员工实际需求
All the following statements about cost baseline are correct EXCEPT: （）.
A．It is a time phased budge
B．To measure disbursements, a spending plan can be used as a cost-baselin
C．It is used to measure and monitor project performanc
D．All projects have one cost baselin
