The speculum of this bird has a very beautiful color.

In physics class, I learned about the properties of convex mirrors.

This magic mirror came from China.

He attached a new reflector to his bicycle.

He was observing the stars with a telescope.

He is good at reading mirror writing.

He conducted an experiment using a spherical lens.

I've decided to go to the gym on Mondays.

She went out to the garden for moon viewing.

Ni is a small child, always full of energy.