The system has been designed to give students quick and easy_______ to the digital resources of the library.

Working hard is not only a _____ of great success, but it is among the essential requirement.

I can't say which wine is better—it's a(n)________of personal taste. 

Please read the _____ on the bottle of the medicine carefully and pay attention to the amount and the time to take the medicine．

Some famous singers live on the ___ from their record sales.