Why should exercise begin 24 hours after surgery?

What should be changed to make the following sentence true? "the stress model suggests that people with a predisposition for a disorder are more likely to develop the disorder when faced with stress."

Why would one lymph node in the neck be swollen and not the other? what causes them to swell?

Avirus consisting of a single strand of rna, which is transcribed into complementary dna, is a ) proteaseb) retrovirusc) rna replicase virusd) nonenveloped virus