I would say the brain, but the heart is also related because the complex concept of love is formed by both bottom-up and top-down processes from the brain to the heart and vice versa.

我想说是脑，但与心也是有关联的，因为恋爱这个复杂的概念即是自底向上的又是自顶向下的，即是从脑到心的，又是从心到脑的。

youdao

Your heart is meant to go far and wide. Your heart is meant to engage again and again, overlapping engagement, layers of engagement, all revealing love.

爱会给你的心留下一条重重的印记，它注定要如此上下求索，它注定要同人的心一再的联结，重叠的，层叠的联结都是爱的启示。

youdao

I love you, my heart used to love you, I have put my heart has been.

我爱你，是一直用我的心来爱你的，我已经把放在我心里了。

youdao

Rowling probably doesn't get compared to Charles Dickens in any other respect, but when it comes to creating larger-than-life characters, she has taken his lessons to heart, and actors must love her for it.

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"He really was a soldier for social justice, and it didn't matter to him your race, creed, color, level of ability, sexual orientation -- he had a heart big enough to love and accept all, " she said.

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"There is absolutely no respect in a comparison like that - this gets to the heart of the problem... the way in which gay and lesbian people love each other has to be honoured and respected, " he said.

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