When you have the brush tool selected, pressing the number keys will adjust the brush opacity.

当你已经选择了画笔工具，按下数字键可以调整画笔的不透明度。

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With the Brush tool selected, you can increase / decrease the brush size by pressing [ or ] key (square bracket key).

在画笔工具被选择的情况下，你可以按下“[”或“]”（左右方括号键）来增大或减小画笔的尺寸。

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Now select Gradient Tool from the layer palette, make sure that default colors are selected (black and white you can activate them simply by pressing D on your keyboard).

选择渐变工具，保持默认颜色（黑色为前景色，白色为背景色），你可以简单的点击工具栏上面的小图标快速设置。

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In the 17th century an ingenious smoker came up with the pipe tamper, or stopper, as it's known in England, a tool for pressing down lit tobacco in the pipe's bowl.

FORBES: Where There's Smoke, There Are Buyers