1. When it's absorbed into a medium, it will affect how things look. It limits the light available to be reflected or transmitted.

2. There's a thing that is called a light filter that is transparent to some kinds of light but is opaque to others. Sunglasses use these material to block out sunlight.

3. A black T-shirt will be a black T-shirt after it is painted, by any colors.

1. If EM waves are absorbed by the medium, they would disapear, and it will affect how things look, because it limits the light available to be reflected or transmitted.

2. Sunglasses are like light filter. It is transparent to some kinds of light and opaque to others. If the sunglasses are in a certain color, the sunglasses will reflect only reflect that color and absorb others.

3. The black T-shirt will always be black even when you mix a large amount of others. Black is the mixture of cyan, yellow, and magenta. Green is the mixture of yellow and cyan. But we cannot subtract magenta from the black T-shirt, so we cannot make a green T-shirt.

1. Absorption would occur, which is the disappearance of an EM wave into the medium. This limits the light available to be reflected or transmitted, thus causing the object to look different.

2. Sunglasses are a type of light filter, which is a material that is transparent to some kinds of light and opaque to others. For example, if the colored covers on sunglasses are red, everything will seem to be red because the other colored lights will be reflected.

3. It is not possible because black is the result of mixing the pigments cyan, yellow, and magenta. Since we cannot subtract one of these pigments from the black T-shirt, we cannot change it into a green one.