Answer:
Randomized
Explanation:
Observational Studies and Randomized Trials are two ideal ways of determining the outcome of certain tests.
In the Observational course the study is conducted in a true to life scenario and the result of what happens is recorded. Meanwhile, in the Randomized Trial there purposefully placed conditions that are ideal and these are evaluated after specific interventions.
Since the pool manager did not let different pools grow algae at will before putting in the chemical this study would not be considered observational. Instead he set up three different pools of the same size with the similar amount of contaminants and then tested the algaecide. This classifies this as a Randomized Trial.
Noun(person place or thing) - new york
Adjective(describing word) - delicious
These poems share a common concern about nature and how the seasons affect the growth of plants and crops.
Stepsister their mother , the fairy godmother and the prince