ӣţţ  ţţƭ  ţţ  ţţ  ţţ½  ţţ  ţţͼ  ţţ¼  ţţ  ţţ½  ţţֱ  ţţ½  ţţ  ţţֱ  ţţ¼  ţţô  ţţô  ţţ  ţţ  ţţֱ