In HDLC protocol, when supervisory frame's type code is '00'. About the following state-ments, which is correct ( )
A. receive ready
B. receive not ready
C. reject
D. selective reject
软件测试是软件开发过程中重要且不可缺少的阶段,测试过程中( )是基础测试。
A. 系统测试
B. 集成测试
C. 单元测试
D. 验收测试
There are several periods in a computer, the longest period is ( ).
A. instruction period
B. machine period
C. beat period
D. CPU period
在目前流行的大多数PC机中,硬盘一般是通过硬盘接口电路连接到( )。
A. CPU局部总线
B. PCI总线
C. ISA总线
D. 存储器总线