shelf是什么意思？

The brain is a seemingly endless library, whose shelves house our most precious memories as well as our lifetime's knowledge.

There is no shelf life on intelligence.

Decades ago, Kodak anticipated that digital photography would overtake film — and in fact, Kodak invented the first digital camera in 1975 — but in a fateful decision, the company chose to shelf its new discovery to focus on its traditional film business.

Place the tea on a lower shelf next time.

Oh, yes, go down this aisle, pass the garden tools, you'll find them on the shelf next to the light bulbs.