A punctuation question with a joining word tests how two parts connect. Find the joining word, then test whether each side can stand alone: each needs a subject, a verb, and a complete thought. Join full sentences with a comma plus a joining word or a semicolon without one. A colon follows a full sentence and introduces an explanation. Verbs sharing one subject usually take a joining word without a comma.
Hints
- Hint 1
Before the blank, find who does what after the phrase about earning a degree. Does that part make a complete sentence?
- Hint 2
Read from she to the end and check for a subject of its own. Can those words stand alone, or do they borrow their subject from before the blank?
Step-by-step
Test both sides of the join
Step 1Test the words after the blank
Read past the blank to she later patented a process. To decide how and joins the parts, can these words stand alone? Yes: she is the subject, and patented is the main verb, the verb that says what the subject does. Although she refers to Torres, this part has a subject of its own, so it doesn't borrow the earlier subject.
- Step 2
Test the words before the blank
Does After earning a degree in mechanical engineering leave the first part unfinished? No, because it's followed by Gabriela Torres began researching biodegradable plastics, which tells us what she did after earning the degree. Torres is the subject and began is the main verb, so this part also stands alone. Both sides are full sentences, which means and needs the punctuation used to join full sentences.
- Step 3
Pair the punctuation with the joining word
Which mark works with the and supplied in every version? A comma and a joining word work as a pair between full sentences. A semicolon would join these sentences without and, while a colon would introduce an explanation; the words she later patented a process add the next event instead. The version with plastics and leaves out the comma, so plastics, and joins these full sentences correctly. Choice B.