Fill in the blanks with appropriate words.
Synthetic fibres are synthesised from raw materials called _______ __.

Explanation

**Step-by-Step Solution:**

1. **Understand the Question**: The question asks for the appropriate words to fill in the blank regarding synthetic fibers and their raw materials.

2. **Identify the Key Concept**: Synthetic fibers are made from specific raw materials. The video transcript indicates that these raw materials are related to petroleum.

3. **Recall the Relevant Term**: The term mentioned in the transcript is "petrochemicals." These are chemical products derived from petroleum, which is a key source for synthetic fibers.

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