1. That rose smells really good - This sentence is talking about the pleasant fragrance of a rose. "Smell" is used as a verb here to describe the action of perceiving the scent through the nose.

2. The dog is smelling Bob's clothing. I hope he can find Bob! - This sentence is talking about a dog using its sense of smell to locate its owner, Bob. "Smelling" is used as a verb here to describe the action of the dog using its nose to detect the scent of Bob's clothing.

3. This soup tastes salty - This sentence is talking about the flavor of a soup. "Taste" is used as a verb here to describe the action of perceiving the flavor through the mouth.

4. He tasted the soup to see if it's OK - This sentence is talking about someone trying the soup to check if it is good or not. "Tasted" is used as a verb here to describe the action of sampling the soup to perceive its flavor.