Characters advance the plot of a story through ? relationships, where their actions lead to results that move the plot along.

Characters advance the plot of a story line through the second option, cause and effect relationships.

the sentence that best describes the tone of the passage from the radio broadcast compared to the passage from the book is b. the radio broadcast has a more surprised tone.

consider the text evidence: in the passage from the book, the description is more matter-of-fact. it is simply describing the things resembling little grey snakes, but there is no urgency in the description. on the other hand, in the passage from the radio broadcast, there is definetely urgency (you can tell from the expression used, "good heavens", which clearly indicates surprise.)

the rigid outer part of the earth, consisting of the crust and upper mantle is the lithosphere.     answer   crust and outer part of the mantle.