President Richard Nixon delivers a goodbye speech to his staff on August 9, 1974.

Mr. Nixon shares an emotional reflection on his mother, highlighting her saintly qualities. The president encourages resilience, emphasizing that true greatness is tested during challenging times. He uses the metaphor of valleys and mountains to illustrate the contrast between life's lows and highs.

What significance does the phrase 'deepest valley' have in the context of the text?

In what way does the text contrast the 'deepest valley' with the 'highest mountain'?