Here is the full statement: A scientist begin working by trying to explain a natural occurrence that is OBSERVABLE.
Scientific method refers to the techniques that scientists used to carry out scientific investigations and it is made up of series of steps. The first step is observation. A scientist normally begin the process of scientific investigation by observing a phenomenon that occur naturally. The observation will lead to questions, which need to be answered and which eventually lead to conduction of experiments.
Venus is the answer. That planet has a dense atmosphere of CO2, which has produced a runaway greenhouse effect.
It's known as severity.
The fact that her pain is on the scale between 1-10 refers to the severity of her pain.
Hope that helped ^U^