An instruction is made up of (41) that specify the function to be performed and operands that represent the data to be operated on. For example, if an instruction is to perform the operation of (42) two numbers, it must know (43) the two numbers are. The processor’s job is to (44) instructions and operands from memory and to perform each operation. Having done that, it signals (45) to send it next instruction.

A．hard disk

B．register

C．memory

D．cache

原油换热系统监控参数是原油流量、温度和换热器两端的（）。

A.流速差

B.液位差

C.压差

D.温差