The answer is:
"They created the most effective public relations campaign in history, inventing techniques that we use to this day."
In the excerpt from "Sugar Changed the World," the author Marina Budhos makes reference to how Clarkson and other abolitionists made the abominations of the slavery system evident to those who made a profit out of it. For example, the exhibition of whips, handcuffs, testimonials and Equiano's memoir.
The lake is described big and beautiful
Sentence structure varies depending on the writer's purpose
a. My father doesn't like dancing but l like dancing.
b. He failed his exam although he studied hard.
c. l was taking my online class while the phone rang.
d. we can learn many more things so that we explore internet.
The 3 in the middle hope this helps!