The function and operation of each un it in the system should be described as well as the location of the units.
应描述系统中各单元的功能和操作，以及各单元的位置。
A.The function and operation of each unit in the system should be described. The location of the units shouldn't* be described. B.The function, operation and location of each unit in the system should be deleted. C.The function, operation and location of each unit in the system should be described.（扌苗述）正确答案C
