Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous:
a sheet of plane glass

Explanation

To classify a sheet of plain glass as opaque, transparent, or translucent, and luminous or non-luminous, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Opaque, Transparent, and Translucent:**
- **Opaque Objects:** These do not allow light to pass through. Examples include wood and metal.
- **Transparent Objects:** These allow light to pass through clearly, enabling us to see objects on the other side. An example is a sheet of plain glass.
- **Translucent Objects:** These allow some light to pass through but scatter it, making objects on the other side appear blurry. Examples include frosted glass or wax paper.
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