The ankle, knee and elbow joints are all ...... joints.

Explanation

**Step-by-Step Solution:**

1. **Identify the Joints in Question**: The question refers to the ankle, knee, and elbow joints.

2. **Understand Joint Types**: Joints in the human body can be classified into different types based on their structure and movement capabilities. The major types include synovial joints, fibrous joints, and cartilaginous joints.

3. **Focus on Synovial Joints**: The ankle, knee, and elbow joints are all classified as synovial joints. Synovial joints are characterized by a joint cavity filled with synovial fluid, which lubricates the joint and allows for smooth movement.

...