What are fossils? How are they formed? Describe in brief two methods of determining the age of fossils.

Explanation

### Step-by-Step Solution:

1. **Definition of Fossils**:
Fossils are the preserved remains or traces of dead plants and animals. They provide evidence of past life on Earth.

2. **Formation of Fossils**:
Fossils are formed when dead organisms are not completely decomposed. This can happen under specific conditions where the remains get trapped in substances such as tree resins, volcanic lava, or hot mud. Over time, these materials harden and preserve the organism's body parts, leading to the formation of fossils.

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