解释以下说法正确与否:(1)如果一家企业的拥有者不给自己支付工资，则会计成本为零，而经济成本为

解释以下说法正确与否:（1)如果一家企业的拥有者不给自己支付工资，则会计成本为零，而经济成本为

解释以下说法正确与否:

(1)如果一家企业的拥有者不给自己支付工资，则会计成本为零，而经济成本为正。

(2)会计利润为正的企业不一定经济利润也为正。

(3)企业雇佣了一些目前处于失业状态的工人，则其使用这些工人服务的机会成本为零。

Please explain whether the following staleness are true or false.

a. If the owner of a business pays himself no salary , then the accounting cost is zero, but the economic cost is positive.

b. A firm that has positive accounting profit does not necessarily have positive economic profit.

c. If a firm hires a currently unemployed worker, the opportunity cost of utilizing the worker' s services is zero.