Hello!
Towering trees relates to an umbrella as in the way that they both give off shade and a form of shelter. Trees and umbrellas can both be protective under certain circumstances.
Cool shade relates to a glass of lemonade because they both offer a colder/refreshing feeling. Cool shade can cool a person down in warm weather and a glass of lemonade can also help to cool a person down on a hot day.
I hope this helps you! Feel free to comment or PM me if you have any additional questions! Have a great day!
