Khaki is a strong cotton or wool fabric of a dull brownish-yellow colour, used especially in military clothing.
How do those lines apply to your life? This isn't a question that has one correct answer, but it could be figured that you eat bread right? If you're trying to be philosophical about it, you could talk about how the thunder accompanies the rain and plants are fed by rain, you are fed by plants therefore you shouldn't fear the thunder. This question is entirely up for interpretation.
What is the underline words