The design feature of（ ） refers to the property of having two levels of structures, such that units of the primary level are composed of elements of the secondary level.
A.arbitrariness B.creativity C.duality D.displacement正确答案C
The design feature of（ ） refers to the property of having two levels of structures, such that units of the primary level are composed of elements of the secondary level.
A.arbitrariness B.creativity C.duality D.displacement正确答案C
