中国大学MOOC: When doing presentaion, we should use some rhetorical devices to enhance the expression.For example, ambiguity, uncertainty,and madness is ___

What are basic types of speaking on special occasions? A: speeches of introduction B: speeches of award presentaion C: speeches of acceptance D: speeches of tribute E: speeches of welcoming F: speeches of farewell

When doing presentaion, we should use some rhetorical devices to enhance the expression.For example, "ambiguity, uncertainty,and madness" is ___ A: group of three B: using contrast C: humor and suprise D: metaphor