25.3.1—The lines in the emission and absorption spectra

understand that the lines in the emission and absorption spectra from distant objects show an increase in wavelength from their known values.

Use —the lines in the emission and absorption spectra to connect the rule to the data and decision in the question.

This matters because —the lines in the emission and absorption spectra determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the lines in the emission and absorption spectra to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The lines in the emission and absorption spectra is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.