I find that a slightly transparent shell gives a better effect, so by default this value is 225 (out of 255 which is a solid [opaque] shell).

一定透明度的shell将提供更佳的效果，所以默认该值是225(255则为一个完全[不透明]的shell)。

youdao

For example, if you have an application with a blue background, which then renders a slightly transparent image over it, you will render all of the pixels in the application twice.

例如，如果您有一个具有蓝色背景的应用程序，随后要在该背景上呈现略微透明的图像，则要呈现两次应用程序中的所有像素。

youdao

Box jellyfish can not only move more rapidly than other jellyfish due to their slightly different structure but are also significantly more beautiful as they are almost transparent.

盒装水母并不能像其他水母那样快速的移动，由于它们那略微不同的结构，但是也是因此他们具有更加引人注目的美丽- - -因为它们几乎是透明的！

youdao

The public art installation is designed in such a way that not only is the noise of the city miraculously blocked out, but one cannot escape getting slightly sprayed by the inspirational mist enshrining twelve panels of transparent glass behind the waterfall.

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