【正文】
nd happened to be back when she left the key in the house. 答案: To 5. The entrance________ the valley was covered ________ some grass and flowers. 答案: to, with 6. We happened to see the thief39。s face clearly______ the light of the moon. 答案: by 7. The bedroom also served________ a study and it was where she finished all her research work. 答案: as