Final answer:
To answer the student's question, isotherms are lines that connect points of equal temperature, and drawing them correctly involves estimating values where necessary. States with the lowest and highest temperatures should be shaded to represent cold and warm air masses, respectively.
Step-by-step explanation:
The question you've asked involves interpreting a weather map of the United States and performing two tasks. First, you need to draw isotherms, which are lines connecting points of equal temperature. These should be drawn so they don't intersect, and some values may need estimation. Following this, you need to identify warm and cold air masses by locating the states with the lowest and highest temperatures respectively and shading them in blue for cold and red for warm.
When completing this task, remember that the United States primarily uses the Fahrenheit temperature scale, even though most scientific work is conducted using Celsius or Kelvin. Pay attention to the legend provided on your map to ensure accurate placement of isotherms and proper identification of temperature extremes. The information about high and low pressure regions and their corresponding letters (H for high, L for low) might be useful for understanding the distribution of temperatures as they influence weather conditions.