Which word in the sentence is a gerund?
a. pounding
b. blowing
c. driving
d. exciting

The correct answer is: c. driving  The gerund is always formed with the suffix ing. It has no irregularities. It is also called the form "ing" or present participle. The gerund is used to form continuous times, it is also used as a subject of the phrase if it is put at the beginning.  

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explanation:

i guess

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.)