According to the doppler effect, the sound of a police car siren is and pitched as it approaches the observer.

On the basis of the Doppler effect, the sound of a police car siren is louder and higher pitched as it move towards the observer.

Explanation:

Whenever the police car with a siren moves towards an individual, the frequency of the siren will increase and the reverse happens when the police car moves away from the person. The individual can listen to the sound of the siren louder and clearer when the car approaches the individual, as the sound is highly pitched when it moves towards the observer. This phenomenon is known as the Doppler effect.

burning of wood and coal

explanation:

the panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth's temperatures over the past 50 years.

you didn't give any options but heres what i can tell you: an inference is likely to change based on additional observations. the latter is something that you have seen or sensed using your sensory organs while the former is like a conclusion out from what you have observed.