单项选择题 Suppose that the current price in a market for Pizza is $9. At that price, the quantity demanded is 519 and the quantity supplied is 400. In this market, we would expect that:

单项选择题 （单选）板框过滤机进行恒速过滤，洗涤时间和辅助时间之和一定时，（）*

单项选择题 定时计数器T1的启动控制位( )，该位置1启动定时器T0工作，T0开始计数，该位置0关闭定时器工作，T0停止计数。