Understanding the Sentence Context

The question asks us to fill in the blanks in a sentence describing an event on an airplane during turbulence. We need to choose the correct pair of verbs that fit grammatically and contextually.

The sentence structure is: "As the plane ________ through the turbulence, passengers ________ their seatbelts tighter." The word "As" indicates that two actions were happening around the same time.

Analyzing the Blanks

First Blank: Plane's Movement

• The sentence requires a verb describing the plane's motion through turbulence.
• The structure "As the plane..." typically requires a past tense verb to indicate the action that was occurring when something else happened.
• Let's examine the options for the first blank:
  • flew (Option 1 & 2): Simple past tense of 'fly'. Fits grammatically.
  • flown (Option 3): Past participle. Needs an auxiliary verb like 'had' (e.g., 'had flown'), which isn't suggested by the sentence structure.
  • flying (Option 4): Present participle. While it can be used in clauses starting with 'As', it usually implies a continuous action requiring an auxiliary verb (e.g., 'As the plane *was* flying...'). Standing alone, "As the plane flying..." is grammatically awkward in this context.
• Based on standard grammar and the options provided, flew is the most suitable choice for the first blank.

Second Blank: Passengers' Action

• This blank describes what the passengers did with their seatbelts in response to turbulence.
• We need a past tense verb that means securing or tightening something.
• Let's examine the options for the second blank:
  • grabbed (Option 1): Means to seize suddenly. While passengers might grab their seatbelts, 'fastened' is more specific to the action of securing them.
  • fastened (Option 2): Means to attach or secure something, like a seatbelt. This is the most appropriate verb.
  • hold (Option 3): Present tense verb. Incorrect as the actions are happening in the past.
  • held (Option 4): Past tense of 'hold'. Similar to 'grabbed', it's less precise than 'fastened' for seatbelts.
• Fastened is the most accurate verb for securing seatbelts.

Selecting the Correct Option

Combining the analysis for both blanks, the pair that fits best is flew and fastened.

• Option 1 (flew, grabbed): Grammatically possible, but 'grabbed' is less precise.
• Option 2 (flew, fastened): Both verbs are past tense and contextually appropriate. "As the plane flew through the turbulence, passengers fastened their seatbelts tighter." This sentence flows well and makes sense.
• Option 3 (flown, hold): Grammatically incorrect.
• Option 4 (flying, held): Grammatically awkward/incorrect for the first blank, and 'held' is less precise than 'fastened'.

Therefore, the correct option is the one containing flew and fastened.