Answer:
The correct statment would be: "the hormons of the endocrine system exert their action by lock and key mechanism."
Explanation:
The endoncrine system is responsable of the release of hormons under certain conditions, and in different organs, they go trough the bloodstream. The lock and key mechanism is explained as how the receptors block or release hormonos or instead they don´t. The endocrine system is responsable for the reproductive system, and regulates metabolic processes.
They smuggled goods because they believed they were unfairly taxed by the sugar act.
Answer:
The description corresponds to an observational study.
Explanation:
In Observational studies, researchers observe the effect of a risk factor without changing what is exposed to it or its conditions. On the other hand, in an experimental study, researchers can introduce a change and study the effects of it.