驾驶人因服兵役、出国（境）等原因无法办理审验时，延期审验期限最长不超过多长时间？
A．1年
B．2年
C．3年
D．5年
参考答案：C
He met many problems ________ he was going over his lessons. [ ]
A. before
B. as soon as
C. since
D. while
用来设置窗体背景图片的属性是
A．Moveable
B．Picture
C．ForeColor
D．WindowState
