A modifier question tests whether an opening describing phrase points to the right person or thing. Read the phrase and ask who or what it describes; if it says something was done, ask what it was done to. The phrase must describe the main noun in the sentence after its comma. Find that main noun, then read the whole sentence with it. Wrong choices can include the right name while putting something else in the place the phrase describes.
Hints
- Hint 1
Read the opening phrase as a question: who or what was considered experimental?
- Hint 2
Find the main noun after the opening comma. Test whether that noun could be what people initially considered experimental.
Step-by-step
Match the opening phrase to its main noun
Step 1Name what was experimental
Initially considered experimental describes something but doesn't name it, so we need a main noun that gives this phrase the right meaning. Who or what was considered experimental? The ending for commercial flights points to the aircraft being approved to fly, not the people approving it. The opening describes the aircraft, which must be the main noun after the comma.
- Step 2
Check what each start makes experimental
What is the main noun, the person or thing the sentence is about, after Initially considered experimental? The start engineers certified puts engineers first, and within just two years, engineers does too because the extra words only say when. Both versions make the engineers experimental instead of the aircraft. In certification for the rocket plane, certification is the main noun, while for the rocket plane only tells us what the approval is for. These starts make the engineers or the approval experimental, rather than naming the aircraft the opening describes.
- Step 3
Read the sentence with the plane first
In the rocket plane was certified, the plane is the main noun, so the opening can describe it directly. The words was certified are a passive form, which tells us what was done to the main noun rather than what it did. Reading on to for commercial flights within just two years gives a complete sentence about the plane receiving approval to fly. Choice D.