The type of waves that can be used to clear a blockage from small tubes are sound waves and visible light.
1. Sound waves can be used to clear blockages by creating vibrations that can dislodge the obstruction in the tube. The energy from the sound waves helps break up the blockage and allows it to move through the tube more easily.
2. Visible light can also be used to clear blockages in small tubes through techniques like laser ablation. Laser light can be focused on the blockage to break it down or vaporize it, opening up the tube for proper flow.
In the context of the given options:
- X-rays are not typically used to clear blockages in tubes.
- Radio waves are also not commonly used for this purpose.
Therefore, the correct answer is: visible light and sound waves.
