David was too tired,he()on the floor and fell asleep

正确答案：填lay即；David was too tired,he ( lay ) on the floor and fell asleep。翻译：大卫太累了,他躺在地板上睡着了。解析：lie 的过去式有两种,规则撒谎,不规则躺。所以应该选lay,是lie 的过去式不规则变化。laid,lain 分别是当lay 作下蛋,产卵时的过去式和过去分词。^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^不明白请继续追问,^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^