下列关于钙拈抗剂抗心绞痛的叙述，不正确的是( )

A．扩张冠脉，改善缺血区供血、供氧
B．阻断钙离子通道，阻止钙离子内流
C．心肌收缩性减弱，心率减慢
D．减轻心脏负荷，降低心肌耗氧
E．心肌收缩性增强，心率加快

下列程序的输出结果为______。main ( ){ unsigned int a=65535; int b=-2; printf ( "\na=%d, %u;b=%d, %u,, a, a,b,b);}

A．-1,65535;-2,65534

B．65535,65535;-2,65534

C．65535,65535;65534,65534

D．-1,65535;65534,65534