Answer:
3. In which sentence does an adverb clause modify an adverb? (a.) A full lunar eclipse lasts longer than a partial eclipse. (b.) The scientists studied the sun as the eclipse's shadow swept across Earth. (c.) When people did not understand the science behind an eclipse, they were afraid of the solar and lunar events. (d.)We used safety goggles when we viewed the eclipse.
Step-by-step explanation:
The answer is: (a.) A full lunar eclipse lasts longer than a partial eclipse.
For although the adverbial clause is elliptical, a partial eclipse modifies a complete one, since it lasts longer, and the other lasts less.