训练结束后，教练让我们放松一下肌肉。

After the workout, the coach told us to ___slacken our muscles.

随着会议接近尾声，讨论的激烈程度开始减弱。

As the meeting drew to a close, the intensity of the discussion began to ___slacken.

学期末的时候，他的学习态度明显松懈了。

His study attitude clearly ___slackened near the end of the semester.