Description Mom Is Sick . Even when she is sick, Mom is always cleaning up messes. Will she ever get any sleep? Zap, Zap, Zap! . Bill, Nell, and Zack get to play with some zap guns. It is an afternoon of fun and lasers! The phonemes /j/v/w/x/y/z/zz/ are featured in this title. In Level 3 - Yellow books, children build on the letter-sound combinations learned in levels 1 and 2. They learn consonant digraphs (sounds made up of two letters together such as 'ch' or "ll") and long vowel sounds (such as 'igh' or 'ai').