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

Explanation

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

### Step-by-Step Solution:

1. **Understanding Opaque, Transparent, and Translucent**:
- **Opaque**: Objects that do not allow light to pass through them. No light can be seen through these objects.
- **Transparent**: Objects that allow light to pass through completely, enabling a clear view of objects behind them.
- **Translucent**: Objects that allow some light to pass through but scatter it, making objects behind them appear blurry.
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