But when the emotion that leads to stiffening the lip is more intense, and involves strong muscle tension, facial feedback may heighten emotional response.

但是当导致嘴唇僵硬的情绪变得更加强烈，并导致肌肉强烈绷紧时，面部表情反应就可能会增强情绪反应。

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You 'll get tough and strong muscle.

你的肌肉会变得强壮有力的。

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Your heart is a big, strong muscle that pumps blood around your body.

你的心脏其实就是一块大大的，有力的肌肉，它可以将血液输送到你的全身。

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Anesthesiologists paralyze patients undergoing sensitive surgeries on the spine, brain or heart by bathing cellular receptors with strong muscle relaxants.

FORBES: Magazine Article

Khan and His Shrines warn that this so-called "Land of the Freak" is where only the strong survive, but it's a strength that can't be measured in muscle.

NPR: King Khan And The Shrines: 'Freak' Show

This is a condition that causes the sudden onset of sleep paralysis the loss of muscle tone that occurs when we sleep during waking hours, often as a result of strong emotions.

FORBES: Defending The Narcolepsy 'Date Rape' Drug