What is sieving? Where is it used?

Explanation

### Step-by-Step Solution:

1. **Definition of Sieving**:
- Sieving is a method of separation used to separate solid particles based on their size. It involves the use of a sieve, which is a device with holes that allows smaller particles to pass through while retaining larger particles.

2. **How Sieving Works**:
- In the sieving process, when a mixture of different-sized particles is placed on a sieve, the finer particles (like flour or sand) pass through the holes of the sieve. In contrast, larger impurities (like pebbles or stones) remain on top of the sieve.

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