定期锻炼能显著改善你的血液循环。

Regular exercise significantly improves your ___circulation.

寒冷的天气有时会导致四肢血液循环不畅。

Cold weather can sometimes lead to poor ___circulation in the extremities.

医生解释说，这种药物通过促进全身的血液循环来发挥作用。

The doctor explained that the medication works by enhancing blood ___circulation throughout the body.