编写要求：
股价在5,10,20,30,60,90,120,250所有均线下方选股公式。
www.gszx.com.cn网解答：
xg:C<MA(C,5) AND C<MA(C,10) AND C<MA(C,20) AND C<MA(C,30) AND C<MA(C,60) AND C<MA(C,120) AND C<MA(C,250);
