根据汉语提示，在句中填写适当的短语。

1. We must_____(保护环境)around us in order to make our homeland more beautiful.

2. Everyone of us should devote ourselves to keeping           (生态平衡)．

3. Let's       __ (收拾干净)the broken glass before someone walks on it．

4. It is everyone's duty to save the    _    (能源)．

5. We often      __  (利用)these waste things to make something else.