It is important to keep our rivers and lakes clean.

保持河流和湖泊的清洁很重要。

同一单元的其他句子

• We should protect the environment for future generations.我们应该为子孙后代保护环境。
• Recycling paper and plastic helps reduce waste.回收纸张和塑料有助于减少浪费。
• Don't throw rubbish into the river.不要把垃圾扔进河里。
• Trees give us clean air to breathe.树木给我们提供清洁的空气呼吸。
• Why is it important to save water?为什么节约用水很重要？