When light travels through a material, such as glass, water, or even air, it moves more slowly.

However, they do not find it easy to make their way up extremely smooth surfaces such as glass.

Materials such as glass, stone, timber and steel are often included in his works.

They also can not climb smooth surfaces such as glass.

Her sculptures use materials such as glass, paper, metal and leather.

He has also done works of art by himself using resources such as slate and glass.

Heat treatments are also used in the manufacture of many other materials, such as glass.

I do not see any reason why this should apply to materials such as metals, paper and glass.

Various methods are used to separate waste materials, such as paper, metal and glass.

He sometimes made small models out of materials that refer to the earth, such as glass.