The student is thinking about the day/night cycle, but they're getting a few things mixed up. Here's why it's unlikely that the sun is hidden behind clouds at night:

* The Earth Rotates: The reason we have day and night is because the Earth rotates on its axis. As the Earth spins, different parts of the planet face the sun (daytime) and then turn away from the sun (nighttime).

* The Sun's Position: The sun doesn't actually "move" across the sky. It appears to move because of the Earth's rotation. At night, the Earth has rotated so that the sun is on the other side of the planet, out of our view.

* Clouds Don't Block the Sun Forever: While clouds can temporarily block the sun during the day, they don't stay in place long enough to obscure the sun for the entire night.

Here's a simple explanation: Imagine a giant ball (the Earth) spinning. One side of the ball faces a light (the sun) while the other side faces away. That's why we have day and night. The sun isn't hidden behind clouds, it's just on the opposite side of the Earth.