Letters that make lower-case letter
s, a, o, e, l, c, r, t, w are letters that make 'lower-case letter'
Words within lower-case letter
ER, lower, letter, te, LET, SE, owe, TT, low, as, let, case, AS, CA, Low, LE, As, Ca, Er, Se, Te are words within 'lower-case letter'