To preach to deaf ears; to talk to a brick wall; to cast pearls before swine (idiomatically refers to explaining something profound or reasonable to someone who is unable to understand or appreciate it, often implying futility or criticizing the listener's ignorance).
和她解释这些复杂的概念简直是对牛鼓簧，她根本听不懂。
Explaining these complex concepts to her is like talking to a brick wall; she simply can't understand.
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