Answer:
Rr Rr
Explanation: The parents of the cat have to have an R allele to be a curled cat, but they can't be RR because that is a dominant gene, meaning that the recessive trait cannot happen. This means that the parents have to have a recessive trait, which means that they are heterozygous.
Essentially, when you breathe in the lung take in oxygen and pass it along to the bloodstream, which brings it to your bodies cells. In return it picks up carbon dioxide, which the lungs dispose of. Every time you breathe this process is happening. That is why it's crucial to keep your lungs healthy.