Knowledge of sexual reproduction (almost always used with the)(noun)
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Use "facts of life" in a sentence
"For Górky, the Bitter One, is essentially a Russian in his grasp on the facts of life and in his treatment."
"Until he was forty he was a believer in English Protestantism; afterwards he could not reconcile current beliefs with the facts of life as he saw them, and had to reconstruct his creed from the foundations."
"They may deny God's freedom, or even His personality, and their necessitarian metaphysics may be radically at variance with the true doctrine of His providence and grace; they may attempt to explain the thought processes of the brain, and even life itself, by physical and chemical laws; yet their impression of the co-ordinated facts of life and nature is thoroughly Calvinistic."