Costs included in the determination of a company’s economic profit that are most likely to be included in that company’s accounting costs are:（）

A. explicit costs.

B. implicit costs.

C. opportunity costs associated with labor provided by the company’s owners.

用钝头牙周探针探测牙周炎患牙的炎症牙龈时，探针终止于（）

A.龈沟底

B.进入结合上皮1／3～1／2处

C.穿透结合上皮，终止于正常结缔组织冠方

D.终止于正常结缔组织纤维内

E.终止于结合上皮的冠方