This is extremely important, because it determines how fast and at what light sensitivity (ISO) your camera can shoot in different lighting conditions.

光圈非常重要，因为它决定你的相机在不同照明条件下拍摄速度有多快，以及拍摄时的感光度(iso)为多少。

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Light, fast and ridiculously sharp, the only problem is how the hordes won't give you time to pose dramatically and whisper haiku after each killing stroke.

轻、快以及夸张的锋利，唯一的问题就是僵尸群不会在你每次攻击后给你时间让你摆个夸张的姿势再吟两句俳句。

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With recent advances in technology over the past several years, many groups of scientists have been investigating exactly how fast light can travel.

随着过去几年间技术上的进步，许多科学家团队都进行了精细的研究来验证光速。

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Shining an appropriate light on such a wire from the outside would alter its refractive index (a measure of how fast light travelling inside the wire can move).

ECONOMIST: New-age crystals

Astrophysicists can determine how the blazar grew brighter in different parts of the spectrum at different times and refine their models of how fast-moving particles within the jets give rise to the high-energy light.

BBC: Blazar Markarian 421's flare-up is cosmic coincidence