科学家正在调查晒伤和皮肤癌之间的关系。

Scientists are investigating the ___relationship between sunburn and skin cancer.

心灵与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.

饮食和健康之间有很强的关联。

There is a strong ___relationship between diet and health.