Sharapova's left hand is starting to move out in front of her to track the ball.

莎拉波娃的左手开始在身前移动跟踪球。

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If touch isn't your thing, the phone also has a slide-out keyboard that works well enough, as well as five navigation buttons and a track ball.

如果对你来说屏幕不是问题的话，这个手机还有一个工作的够好的滑盖键盘以及五维导向按钮和轨迹球。

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We made a special ball, with a bell in it, so the kids can keep track of where the ball is and what it's doing by listening for it.

我们做了一个特殊的足球，里面带一个铃铛。这样通过铃铛声音，孩子们可以跟着球跑并能判断出赛场情况。

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It again uses cameras to track the ball and computers to calculate its position.

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"It was going to be difficult chasing 200 plus on a track where the ball is going up and down, " said Tendulkar, who was named man of the match and man of the series for scoring 403 runs at an average of 134.5.

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Most existing pinball machines use mechanical microswitches to keep track of where the ball is.

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