晒伤和皮肤癌之间存在明确的关联。

There is a clear ___relationship between sunburn and skin cancer.

心智和身体之间的关系已被科学家证明。

The ___relationship between mind and body has been proved by scientists.

饮食和健康之间的关系有充分记录。

The ___relationship between diet and health is well-documented.