-0.5表示为IEEE754标准短实数的机器数形式为()
A11000000010000000000000000000000
B11000000000000000000000000000000
C10111111000000000000000000000000
D01111111100000000000000000000000
A11000000010000000000000000000000
B11000000000000000000000000000000
C10111111000000000000000000000000
D01111111100000000000000000000000