def METHOD_NAME(sent):
    ns = []
    regex = re.compile("[^a-zA-Z0-9 ]")
    for p in sent:
        if (not regex.search(p)) or p == FAIL_SENT:
            if p == " " and (len(ns) == 0 or ns[-1] == " "):
                continue
            ns.append(p)
    return ns