Aspeakers use of in a speech allows a speaker to invoke concepts that the audiance is already familar with ?

The answer in the blank, i believe is common themes. It is because using common themes or including them on the speaker's speech could make the audience relate on the topic and to be intrigued or to be interested. With this method, not only will the speaker give out his information but he or she could capture the attention of the audience.

The correct answer would be sentence 3 and sentence 6 i should know because i just passed the text and got  %100