A punctuation question with comments inside other comments tests whether you can track each pair of marks. Look back from the blank for the opener, then cross out the whole insert, extra information the sentence can do without. An insert in the middle must open and close with matching marks. Next, check the subject, who or what the verb is about: use a comma before and between two full sentences, but not between two verbs with the same subject.
Hints
- Hint 1
Look back from the blank to the words beginning a breakthrough. Find the mark that opens this extra information.
- Hint 2
Cross out according to industry analysts first. Which punctuation marks belong to that smaller comment, and which larger piece of extra information remains?
- Hint 3
Read the sentence with the whole comment in parentheses removed. Who or what lowers the costs, and is a new subject stated after and?
Step-by-step
Find the inserts, then uncover the joined verbs
Step 1Find the outer opener
Look back from the blank to 40 percent (a breakthrough that,. Which mark opens the extra information we're working through? The parenthesis opens an insert, a comment about the drop in energy use. To complete the sentence, we need to find the insert's end and see how the sentence continues.
- Step 2
Sort out the inner commas
The commas in that, according to industry analysts, belong to a smaller insert. Do they close the larger one? They set off according to industry analysts, so they close only the inner insert. Cross out that comment, and the breakthrough's description runs on through its possible effect on drought-prone regions.
- Step 3
Uncover the two verbs
Where does the sentence pick up again? Cross out the whole comment from the opening parenthesis through regions, and read the key words that remain: methods that reduce energy consumption ... and lower operational costs. The word that points back to the methods, so reduce and lower both tell us what the methods do. No new subject follows and, so it joins two verbs rather than two full sentences. Both verbs share one subject.
- Step 4
Close the insert without an extra break
Use a closing parenthesis to match the opener, then check whether another mark is needed. A comma before and joins two full sentences, but and lower operational costs has no new subject and doesn't start another comment, so no comma or dash is needed. The completion is regions). Choice D.