医生再三强调保持健康饮食的重要性。

The doctor keeps ___stressing the importance of maintaining a healthy diet.

最近工作太多，他开始感到压力很大。

With too much work recently, he's been ___stressing a lot.

搬运重物时要小心，不要过度用力伤到背部。

Be careful not to ___stress your back when lifting heavy objects.