根据对角线的长可以求得菱形的面积，
根据S=12×4cm×23cm=43cm2，
故答案为：43．
---It’s 12 April today. Have they found any useful information about the plane's black box?
---Flight MH370? Yes, but it’s difficult to decide where the black box really is.
A．still
B．ever
C．yet
D．never
坚持:突破
A．学习:发展
B．赞同:争论
C．继承:创新
D．团结:竞争
