中共十七大报告指出，我国“市场体系不断健全，宏观调控继续改善，政府职能加快转变”。下列行为属于宏观调控经济手段的是( )。

A．国家提高农产品收购价格

B．物价部门核准公共交通的价格

C．国家修订个人所得税法

D．工商部门给新办企业发放营业执照

In the open systems interconnection (OSI) reference model, "layer" means one of seven conceptually complete, (71) arranged groups of services, functions, and protocols, that extend across all open systems.

Application layer provides means for the application (72) to access the OSI environment. Presentation layer provides for the selection of a common syntax for representing data. (73) layer provides the means necessary for cooperating presentation entities to organize and synchronize their dialog and to manage their data exchange. Transport layer provides a reliable end-to-end data transfer service. Network layer provides for the entities in the transport layer the means for transferring blocks of data, by (74) and switching through the network between the open systems in which those entities reside. Data link layer provides services to transfer data between network layer entities. Physical layer provides the mechanical, electrical, functional, and procedural means to establish, maintain and (75) physical connections for transfer of bits over a transmission medium.

（74）处填（）。

A．passing

B．linking

C．searching

D．routing