Answer:
In the Dead Sea, they found that the rate of evaporation peaks during the day just a few hours after solar radiation peaks.
Mutualism is when both sides benefit. The hummingbird gets nectar and the flower is benefited because the hummingbird that has been to other flowers carry pollen on its body which spread the flower when it sucks its nectar, therefore pollinating the flower in the process.
The tropics are probably very moist, making a perfect environment for organisms as their habitat.