1. 影响;作用
    The impact that something has on a situation, process, or person is a sudden and powerful effect that it has on them.

    e.g. They say they expect the meeting to have a marked impact on the future of the country...
           他们称他们预期会议对国家的未来会产生显著影响。
    e.g. The major impact of this epidemic worldwide is yet to come...
           这种传染病在世界范围内的重大影响还未完全显现。

2. 撞击;碰撞;撞击力
    An impact is the action of one object hitting another, or the force with which one object hits another.

    e.g. The plane is destroyed, a complete wreck: the pilot must have died on impact...
           飞机遭到毁坏,完全成了一堆残骸：飞行员肯定死于撞击。
    e.g. A running track should be capable of absorbing the impact of a runner's foot landing on it.
           跑道应该能够吸收奔跑者踩踏地面时产生的撞击力。

3. (对…)产生影响
    To impact on a situation, process, or person means to affect them.

    e.g. Such schemes mean little unless they impact on people.
           这些计划没什么意义,除非它们对人民产生影响。
    e.g. That, in turn would increase pressure for higher wages and that, in turn, would impact on inflation and competition.
           那样就会增加工资上涨的压力,而那样又会对通货膨胀和竞争产生影响。

4. 撞击;冲击;碰撞
    If one object impacts on another, it hits it with great force.

    e.g. ...the sharp tinkle of metal impacting on stone...
           金属撞击石头发出的刺耳叮当声
    e.g. According to the air force, the missile merely impacted with the ground prematurely...
           根据空军提供的消息，导弹只是提前撞向了地面。