单项选择题
A. void define WORD B. as_b3 _123 If C. for -abc cas D. 2c Do SIG
A. 1/3*sin(1/2)*sin(1/2) B. sin(0.5)*sin(0.5)/3 C. pow(sin(0.5),2)/3 D. 1/3.0*pow(sin(1.0/2),2)