When you are using the Marquee tools or Free Transform, hold down Opt + Shift + drag will scale proportionally from the center.

当你正在使用选框工具或自由变换，按住组合键opt + Shift的同时再用鼠标拖动可以从中心按比例对对象进行按比例缩放。

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To start, choose the Rectangular Marquee Tool from the Tools Panel and create a rectangular selection using the following figure as a guide.

首先，请从工具小组的矩形选框工具并创建一个矩形选择使用为指导，如下图。

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