Original: A saiga's nose warms the air and traps dust.
Rephrased (one word longer): A saiga's nose warms the cold air and traps dust.
Why this works (easy steps):
- Choose a small, useful word to add — here we add "cold".
- Place it where it fits (before "air").
- Count the words to check it's one more. The new sentence still makes the same, simple idea easy to understand.