Why levers usually have a greater mechanical efficiency than other simple machines do?

Explanation

### Step-by-Step Solution:

1. **Understanding Levers**: A lever is a simple machine that consists of a rigid bar that pivots around a fixed point called the fulcrum. It is used to lift or move loads with less effort.

2. **Diagram of a Lever**: Visualize a lever with a fulcrum in the center, a load on one side, and an effort applied on the opposite side. This helps in understanding how levers function.

3. **Fewer Moving Parts**: Levers typically have fewer moving parts compared to other simple machines, such as pulleys or gears. This simplicity reduces the chances of energy loss.

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