弹道学：关于射弹动力学的研究。

Ballistics: the study of the dynamics of projectiles.

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振动频率对回弹动弹模有一定影响，高振频使测定值有所下降。

Vibratory frequency has some effect on measured value of the unloaded dynamic elastic modulus. Higher vibratory frequency may decrease a little the value of the modulus.

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把印着泪水的笺，交给那旅行的水，何时流到你的身边，让弹动你的心弦。

Writing paper to print tear, assign water of travel that, when flow side to reach you, let, play chord to work up you.

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