Respuesta :
Notify the authorities, leave the location, suggest another activity.
Answer: The answers are: Leave the location, suggest another activity and notify the authorities if all else fail.
Explanation: Harmful substances refer to substances that are hazardous to humans. These elements are not good for human consumption and as a result they should not be consumed by humans. They are also dangerous to human health. Examples are food, water, drugs and so on that are unfit for human consumption. Some of these harmful substances can cause asthma or other diseases.