A.數(shù)據(jù)線由低變高B.數(shù)據(jù)線由高變低C.數(shù)據(jù)線不變
A.TIM2_IRQHandlerB.USART1_IRQHandlerC.SysTick_HandlerD.EXTI4_15_IRQHandler
A.if,elseB.do,whileC.while(1),switchD.for(;;)