To be good at hearing, repeating, or understanding a particular type of sound is to have an _____ _____ _____
ear for something
something that you have acquired (noun form)
acquisition
To continue working hard at something difficult is to _____ _____ _____
keep at something
The activity of talking and doing things with other people, or the way that two or more things combine and have an effect on each other (adj, noun, and verb forms)