Answer:
C.
“If there is any practical use for helium other than medicine, laws should change to protect current supplies of the gas.” This sentence summarizes one of the major points of the argument, which is that helium reserves are in low supply.
CLOSELY and HEALTHY are your two adverbs because they end in -ly
Answer: B. In school, my mother encouraged me to join the band.
The modifier in this case is misplaced as it makes it sound like the mother was at school when she gave the advice. Modifiers can be very important to the structure of a sentence as they can significantly change the meaning if misplaced.
All the other examples express the meaning of the sentence clearly.
