问答题

运行下面程序，结果如图表示。(此程序是Logo语言编写)
TO ZFX REPEAT 4[FD ______ RT 90] PU FD 25 RT 90 FD 25 LT 90 ______ END TO TU REPEAT 4 [REPEAT ______ [ZFX] RT ______ REPEAT 4 [ZFX] RT ______] END