What does Zaroff mean when he nods to Ivan?

Does anyone know the answer to the question?

Which important event occurred during the industrial and scientific revolutions

Constructing an argument: in modern american society, the legalization of marijuana continues to be controversial and hotly debated. some people find it contradictory that certain "drugs"—such as tobacco and alcohol—are legalized even though they pose proven health risks, while marijuana, which has many medicinal applications, continues to be illegal by the federal government. what reasons do you think the federal government gives for outlawing marijuana, and do the reasons support the conclusion?