A modifier question tests whether an opening describing phrase connects to the right noun. Read the words before the comma, and name who or what they describe. If the phrase gives a destination and a journey, ask what is making that trip. An opening describing phrase must describe the main noun right after its comma, so find that noun in each choice. A name appearing later in the sentence can't fix a wrong match at the start.
Hints
- Hint 1
The words before the blank describe a trip without naming the traveler. Ask who or what is making that trip.
- Hint 2
For each completed sentence, find the main noun right after the comma. Does that noun name whoever or whatever is bound for Mars?
Step-by-step
Match the opening phrase to its noun
Step 1Name the traveler
The opening words Bound for Mars on a nine-month journey describe something heading toward Mars without naming it. Who or what is making that trip? It's the spacecraft, so this question needs that vehicle as the main noun right after the comma. An opening describing phrase must describe the main noun that follows its comma, rather than any noun mentioned later in the sentence.
- Step 2
Test mission control and the monitoring
Start with mission control and continuous monitoring: could either be Bound for Mars? Mission control is watching the spacecraft, while continuous monitoring is the work of watching it. Those choices make the watchers or their work the main noun, rather than the traveling vehicle. The phrase describes what travels, not what monitors the trip.
- Step 3
Look inside the longer noun phrase
What is the main noun in the life-support systems of the spacecraft? It's systems; of the spacecraft tells us which systems they are. The spacecraft's name is inside a phrase describing the systems, so the spacecraft isn't the sentence's main noun. This version makes the life-support systems the traveler on a nine-month journey, while the opening describes the spacecraft itself.
- Step 4
Read the spacecraft version to the end
In the spacecraft carried a crew, the spacecraft is the main noun, and carried is the verb. What does the rest of the sentence tell us? The words that continuously monitored its life-support systems describe the crew, so they don't change which noun Bound for Mars attaches to. Choice B.