根据以上分析知：
正方形的边长是4cm．
故选：B．
1941年，日本偷袭珍珠港，随后，德国突袭苏联，第二次世界大战的规模进一步扩大。
—The former president of Iraq was caught at last.
—Really? Where himself?
A．has he hidden
B．had he hidden
C．was he hidden
D．has he been hidden
