When light shines on the water,it bounces off the surface,thus shining light everywhere to make the exhibit look brighter and more appealing....[i think this is the answer...]
because of the hotair vapour
They don't, unless the item(s) on display need mild protection from drying out. The water evaporates, keeping the air in the case from becoming too dry. This dry air would in turn dry out the item(s) on display, damaging them.
To provide humidity lost via the hot bright lights.
Extreamly dumb question but hear's your answer. It's called advertising, They sometimes add extra objects into the displays to attract more attention or to give the display it's own meaning. think of summer clothes on a dummy; how would you know it's summer clothes being advertised? it's wearing glasses to show you it's what it is if you get what i mean.
Water expands when it becomes ice.So the glass will break if you put a glass of water inside the refrigerator. I put glasses of water inside my refrigerator all the time.It keeps it cold. If your glass is freezing and breaking you need to check your temp setting.
Water goes inside
Nothing because pouring hot water in glass will do nothing except fogging the glass as you pour the water
Condensation of the cool air on the hot glass.
as the glass attracts water from the light.water have chiken fats inside and it is very nice in order to attract peoples attention
fill inner glass with ice water, immerse outer glass in hot water.
Do you mean the actual glass itself is warm or the water inside? If the water is warm then its a glass of warm water What is the noun you want to modify -- the glass or the water? It's hard to imagine a warm glass containing cold water, but I suppose it's possible.
This is due to condensation. When air comes in contact with the glass it condenses(this happens only when the water inside is cold).