def simplify(text, space=" \t\r\n\f", delete=""):
    """Returns the text with multiple spaces reduced to single spaces

    The space parameter is a string of characters each of which is
    considered to be a space.
    Any characters in delete are excluded from the resultant string.

    >>> simplify(" this    and\\n that\\t too")
    'this and that too'
    >>> simplify("  Washington   D.C.\\n")
    'Washington D.C.'
    >>> simplify("  Washington   D.C.\\n", delete=",;:.")
    'Washington DC'
    >>> simplify(" disemvoweled ", delete="aeiou")
    'dsmvwld'
    """
    result = []
    word = ""
    for char in text:
        if char in delete:
            continue
        elif char in space:
            if word:
                result.append(word)
                word = ""
        else:
            word += char
    if word:
        result.append(word)
    return " ".join(result)