An instruments-only piece played at the opening of an opera is known as a/an a. procession. b. prima prattica. c. aria. d. overture.

The correct answer is D. Overture

An overture is basically an introduction. It consists of only instruments and usually presents the musical themes that will be seen later during an opera. Overtures always come in the beginning and don't include any singing or similar things that might distract from the music since the voices will come at a later time.

The skin in the outer ear canal has special glands that produce earwax. the fance name for this waxy stuff is cerumen.after the wax is produces, it slowly makes its way through the outer ear canal to the opening of the ear.