What is the control in this experiment? why does this serve
periment? why does this serve as the controll

This is s cute awee : (( . well if she's showing you signs that she may like you , then shoot your shot ! don't be afraid . & if you're unsure that she's giving you these signs , then wait out for a little bit . most girls are different . some may act really sweet , but only bc you're a good friend of hers . that , or she might like you . you just never know . but i think you should sit down with her & tell her how you feel . but don't be awkward & shy . just be straight up & tell her how you feel . if the feelings aren't mutual , then don't cry about it . you need to respect her decision & look for others in the world . feelings can be difficult & confusing , but don't be afraid to show them . i say you play it out & if you're still unsure about it , talk to her . - rach

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.