That makes it difficult to preserve vacant space".
Mold, smoke, and moisture have made it difficult to preserve the frescoes.
Lesion-behavior studies, however, suffer from a difficulty in unambiguously dissociating between memory processes (e.g., item versus context memory), making it difficult to conclude that a given process is functionally preserved.
The left or underside of the skeleton was preserved in carbonaceous clay, making it difficult to expose the skin.
Turnout varies, and activists are keen on preserving their non-hierarchical structure, making it difficult to distinguish regular initiates from casual attendees.
Preserving relative branch lengths means some leaves may be far from the attribute bar, making it difficult to identify which attributes correspond to a given leaf.
Unfortunately, it is not preserved by composition, which makes it difficult to exploit with component-based design concepts in mind.
Nichols (2003) counters that such an account makes it difficult to explain how, in some cases (as above), iteration is preserved.
Dr. Zheng's group acknowledged that the way many of the specimens were preserved, revealed only in two dimensions, made it difficult to reconstruct the precise location and orientation of the leg feathers.
This vegetation made it difficult to reach the target sites, which in turn suggests that dense vegetation keeps humans from disturbing weeded areas and that it has contributed to preserve the tsunami deposits from disturbance by humans.
