Pilihlah layer. Pilihlah Opacity. Turunkan opacity.

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in Chinese about that?
在图层列表中，选择你想设置为透明图层的图层。 在图层标签顶部，点击不透明度旁边的数字框。默认的不透明度是100%。 拖动箭头，改变图层的不透明度。如果你想让图层完全透明，你可以将它调整为0。