the story begins with snoopy sleeping on the top of his red doghouse while woods

the story begins with snoopy sleeping on the top of his red doghouse while woodstock
◆译文是：【这个故事是从伍德斯托克音乐节的那天史努比睡在红色的狗窝顶上开始的。】

●【with snoopy sleeping】，因为这个短语前面有个介词with，所以其中的【sleep】用【sleeping】动名词形式。
●句末的while woodstock是时间状语，表述【史努比睡在红色的狗窝顶上】的时间。