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

Explanation

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

### Step-by-Step Solution:

1. **Understand the Definitions**:
- **Opaque**: Objects that do not allow any light to pass through them.
- **Transparent**: Objects that allow light to pass through and you can see a clear image of objects behind them.
- **Translucent**: Objects that allow some light to pass through but do not allow a clear image to be seen.
...