bear的过去式和过去分词和现在分词

　　We followed the bear's tracks in the snow.

　　我们跟着熊在雪地上留下的足迹走。

　　The little boy cuddled the teddy bear close.

　　小男孩紧紧地搂着玩具熊。

　　You people without kids don't know you're born.

　　你们没孩子，真是身在福中不知福啊。