Such programs are much needed because in many arid lands there is only a vague idea of the extent of groundwater resources.

这样的计划是非常必要的，因为在许多干旱地区，我们并不清楚其地下水资源的范围。

youdao

Because most programs are long-lived (some last for decades), there many be an unlimited number of stages in a program.

因为大多数计划都是生命周期较长的(有些可以持续几十年)，因而一个计划中有许多无限量的阶段。

youdao

Because most programs are long-lived (some last for decades), there many be an unlimited number of stages in a program.

因为大多数计划都是生命周期较长的(有些可以持续几十年)，因而一个计划中有许多无限量的阶段。

youdao