Without surrounding context, some of these abbreviations cannot be accurately defined however, the options can be given.
Cu, with a capital C and lowercase u is often the chemical symbol for copper from the periodic table. However, CU, with both letters capitalized can be cardiac unit, chronic urticaria, cholinergic urticaria, and cause unknown.
Cc is often used for chief complaint, critical care, or cubic centimeter, though, less commonly, it could potentially be used for corpus callosum, chronic cough, chronic constipation, creatinine clearance, cervical cancer, and cerebral cortex.
LL can be left lung, lower left (as in lower left extremity), lower lobe (as in the left lung), lower limb, leg length (as in LLD, leg length discrepancy). This is not a commonly used abbreviation.
PI is another one that is not commonly used. This could be primary immunodeficiency, pulmonary infarction, pulmonary insufficiency, post-ischemic (as in post ischemic event), peripheral iridectomy, present illness, or primary infection.
For those last two, I would certainly suggest completely spelling out the words the abbreviations are meant to represent to avoid confusion. Again, context is everything however, "lower lobe" and "lower limb" are completely different things and the last thing we want to do is confuse others in documentation.