What do we call a material that you can see through clearly, like glass?

What do we call a material that you cannot see through at all, like a wall?

What do we call a material that lets some light pass through, but you cannot see clearly through it, like frosted glass?

Which of the following is an example of an opaque object?

Which of these is a transparent object?

What do we call a window that is covered with a curtain that lets some light in but you can't see through it clearly?

Which of these materials can you see clearly through?

Which of the following describes an opaque object?

What do we call materials that allow some light to pass but not enough to see through clearly?