निम्नलिखित में से कौन सी प्रथा भूजल स्तर को पुनः भरकर स्थायी जल संरक्षण में सीधे योगदान देती है?

Prolonged exposure to extreme cold temperatures may result in tissue damage known as frostbite, which is categorized as a:

In the context of ecosystem energy dynamics, which of the following expressions correctly defines Net Primary Productivity (NPP)?