A .............. muscle rotates the forearm to turn the palm downward while a ............ muscle rotates the forearm to turn the palm upward.

Explanation

To answer the question, we need to identify the muscles responsible for the rotation of the forearm in two specific directions: turning the palm downward and turning the palm upward.

### Step-by-Step Solution:

1. **Identify the Action of Turning the Palm Downward:**
- The action of turning the palm downward is known as pronation.
- The muscle responsible for this action is called the **pronator muscle**.

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