Explode The Code Book 6 Introduces Students To Rcontrolled Vowels, Silent Letters, And Vowel Diphthongs And Is Ideal For Students In Grades 24. Skills Addressed Through A Variety Of Encoding, Decoding, And Writing Exercises Include The Rcontrolled Vowels Ar, Or, Er, Ir, Ur, War, Wor,Silent Letters Igh, And Wowel Diphthongs Oo, Ea, Ie, Oi,