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1·This is convenient since when killing the well the pump stroke counter will be used to determine how far the kill has proceeded.

这样做很方便，因为压井时，将使用泵冲记数器来决定已进行的压井走了多远。

2·With the down stroke of a wing during flight, the body moves up, but the subsequent upstroke can counter that force.

用飞行翼的上下行程，身体向上移动，但随后的冲程可以对抗这种力量。