题目

一I still cannot figure out why he missed his flight．一He        an accident on the way to the airport．A．could have had                B．should have had C．would have had                D．must have had 答案：A1．下列过程中属于化学变化的是（（　　）A．水分蒸发B．玻璃破碎C．铁器生锈D．水果榨汁