Therefore, we must economize on energy resources.

因此，我们必须节约能源资源。

youdao

First we must economize the use of water resources and practice a recycling policy.

首先我们务必节约水资源的使用和回收的政策实践。

youdao

First we must economize the use of water resources and practice a recycling policy.

首先我们务必节约水资源的使用和回收的政策实践。

youdao