题目

Most of the passengers were about to sleep_____a terrible train accident_____on April 28th..       A. who; came in      B. if; came on      C. where; came from    D. when; came about 答案：D（2007•云南）一元二次方程3x2-x=0的解是（ ）A．x=0B．x1=0，x2=3C．x1=0，x2=D．x=