Answer:
I'll assume you have to match the name with their definitions.
1. aquifers 
underground water sources  
That's because of the presence of porous rocks that let water pass through them and reach an underground cavern that then acts as a tank.
2. delta  
a broad, triangular-shaped land area at the mouth of a river 
That's common especially in larger rivers that meet their destination point (usually the ocean).
3. oasis  
a small fertile area in the desert, usually a place where water is close to the surface (plural - oases)  
We all heard about oases in the desert, where human and animals alike gather to drink.
4. rain shadow  
an area that receives less precipitation because of its location on the leeward side of a mountain	
That's common in high mountains region where the mountains are so high they block the passage of clouds to the other side.
 
        
             
        
        
        
Explanation:
The physical environment of forests is determined by edaphic (soil) factors and micro-climate (precipitation, light, temperature, and wind). Gas-exchange within forest canopies depends upon the microclimatic condition within the forest, as well as, edaphic factors and water availability.
 
        
             
        
        
        
Answer and Explanation:
- The Columbian exchange basically alludes to the European pilgrim Christopher Columbus who was engaged with boundless trade or move of different plants , crops, societies, creatures, and human populace and technological thoughts between the Americas and rest of the portion of the world or the past world in the fifteenth and sixteenth century.  
- Christopher Columbus was attempting to leave Europe and head west to discover Asia that was his real arrangement however he accidentally found the America.  
- Over the Americas he established a lot of things that he never observed in Africa, Asia or Europe and a few things which were found in the accidentally found district of Americas were items like potatoes, corn, tomatoes and couple of creatures they had never observed that were significant, for example, Llama and furthermore diseases.  
- Discussing the Columbian exchange the individuals which were dwelling in the America, the local Americans never came across things which Columbus brought to them from the ancient world, for example, Bananas, carrots, apples and animals which was significant throughout the entire existence of man, steeds.  
- Columbian exchange the nourishment, plants, crops, organic products, animals, thoughts between the old world and the America were traded.
- Things traded were similarly new and amazing to the two sides of the world( Americas and the ancient world).
This is a case of how worldwide connection changed the human progress in various parts of the world.