Over 70 million:
http://www.nhm.ac.uk/nature-online/collections-at-the-museum/intro-to-our-collections/index.html
You can only hold 20 items at a time.
998 items you can hold
The Science Museum in London displayed the Wright Flyer in 1928.
Unfortunately not, but it is possible to clone items
Citric acids are natural acids coming from lemons and other citrus fruits. They are most commonly found in cleaning substances.
It depends on which position you hold.
Up to 24 items.
The only trainers that you will meet that hold items are trainers in Battle Frontier they only start holding items once you get later in the obstacle.
A:your hand
a lotus flowe....
watch glass?
The clipboard will hold one item; that being the last item that was cut or copied. There are numerous utilities available that will expand the clipboard to hold numerous items.