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.
Answer: Linking words and phrases are used to show relationships between ideas. They can be used to join 2 or more sentences or clauses (a clause is a group of words which contains a subject and a verb). Linking words/phrases can be used to add ideas together, contrast them, or show the reason for something.
Answer:
show or prove to be right or reasonable.