a round trip, going back and forth / (by extension) an exchange (of conversations, letters, etc.) / coming and going

various; a variety of; all kinds of; many; diverse

emit light

目覚まし: waking, waking up (either waking oneself, or waking someone else); a kind of sweet given to children waking up; short for 目覚まし時計 (mezamashi-dokei): alarm clock