A punctuation question with an -ing phrase at the end tests how the sentence's parts connect. Read both sides of the blank and find each side's subject and main verb; an -ing word alone isn't a main verb. Then check how the ending connects: does it complete the thought or add extra information? Periods and semicolons separate complete sentences, a comma sets off an extra phrase, and no punctuation joins words that fit directly into the sentence.
Hints
- Hint 1
Read through the park's name and find the subject and main verb. Do the words before the blank form a complete sentence?
- Hint 2
Look at the phrase beginning with documenting and check whether it can stand alone. Does it have its own subject and main verb?
- Hint 3
Temporarily remove the words beginning with documenting, then ask what they add when you put them back. Does the sentence need them to finish its thought?
Step-by-step
Cross out and test the ending
Step 1Find the complete sentence
Start with Jane Goodall has spent decades: Goodall is the subject, and has spent is her main verb. This punctuation question asks how the ending phrase joins the sentence, so is the sentence complete through the park's name? The words observing chimpanzees tell us what she has spent those decades doing, and the park's name tells us where, so the words before the blank form a complete sentence.
- Step 2
Test the ending phrase
What do the words documenting behaviors once thought to be uniquely human add? They tell us what Goodall did while observing the chimpanzees, rather than finish the thought about where she worked. The phrase adds a detail about her work, not a description needed to identify the park, and the sentence still works without it. Can this extra phrase stand alone? No: documenting has no subject of its own and isn't a main verb by itself, so this ending phrase depends on Goodall's sentence.
- Step 3
Attach the extra information
Which boundary can attach the extra phrase without making it a new sentence? A comma sets off an extra phrase at the end, and the sentence's period closes the thought. The version with a period and the version with a semicolon would force documenting behaviors to stand alone, while the unpunctuated version leaves the extra phrase unmarked. A comma attaches this extra detail to Goodall's complete sentence, giving us Park,. Choice D.