Translation:The food I have just bought is in the refrigerator.
I don't know. May be they wanna mention all foods that they bought was put into the fridge
I though that ở was only for questions. Or someone explained it thusly to me a while back.
"ở đâu" would be the question phrase not just "ở", unless you ask incredulously: "what? the food I just bought are in the fridge?!" otherwise it's meant for a simple statement:
- tôi ở nhà. (I'm home)
- những trái táo ở trên bàn. (the apples are on the table.)
- sông Nin bắt nguồn ở Trung Phi. (the Nile takes its source from the Central African region.)