Halley realised that Mercury was so far away that its parallax angle would be very difficult to determine.

哈雷意识到水星离地球如此之远，以至于很难确定它的视差角。

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As Venus was closer to the Earth, its parallax angle would be larger, and Halley worked out that by using Venus it would be possible to measure the Suns distance to 1 part in 500.

由于金星离地球更近，所以它的视差角会更大。哈雷计算出，利用金星可以测量出太阳与地球之间的距离，误差为五百分之一。

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SI: With this parallax barrier technology, the LCD must be a certain distance away from the screen. It also needs a certain viewing Angle.

岩田聪：这个视差屏障技术需要要求液晶屏幕必须隔着一定的距离才能实现，同时需要一定的角度才行。

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