伤口愈合时会自然脱落死组织。

The wound naturally ___sloughs dead tissue as it heals.

蛇每年都会蜕去旧皮。

Snakes ___shed their old skin every year.

这片湿地有很多泥沼，是水鸟的理想栖息地。

The wetland has many ___sloughs that make perfect habitats for water birds.