1. **Is the object a cylinder?**
   - **Answer:** Yes
   - **Reasoning:** The images show an object with a circular base and a uniform cross-section along its length, which are characteristics of a cylindrical shape.

2. **Is the cylinder hollow?**
   - **Answer:** Yes
   - **Reasoning:** All images clearly depict a space or void running through the center of the cylinder, indicating that it is hollow.

3. **Is the cylinder long?**
   - **Answer:** Yes
   - **Reasoning:** The cylinder appears significantly longer than its diameter in all images, suggesting that it is a long cylinder.

4. **Is the inner radius of the cylinder medium-sized?**
   - **Answer:** Unclear
   - **Reasoning:** Without specific measurements or a reference scale, it is difficult to determine if the inner radius qualifies as medium-sized. The term "medium-sized" is relative and lacks a precise definition in this context.