The changes are insidious, and will not produce a noticeable effect for 15 to 20 years.

变化是悄然发生的，15到20年间不会产生明显效果。

《柯林斯英汉双解大词典》

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But after following 385 patients with type 2 diabetes for 6.5 years, the researchers actually saw the opposite effect.

但随后的跟踪385位有第2糖尿病症状的病人6.5年之后，研究者们实际上看到了相反的效果。

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The scientists estimate this would have the same climate effect as taking all cars in the world off the road for ten years.

VOA: special.2009.06.19

Income inequality has been growing in the US for almost 40 years, with the effect that the core demand for goods and services is being eaten away.

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Panning shots can look jerky if you move the camera too quickly, but moviemakers have battled that effect for years with their 24-frame-per-second equipment.

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That hasn't been in effect for years, they say.

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