Passage Summary: An editorial argues that if you think cell phones are annoying on a bus, they will be a nightmare on a plane because you are trapped in a tiny seat next to the person talking.

Conclusion: The proposal to permit cell-phone usage on commercial aircraft is a poor decision.

Reasoning: Cell phones are already a nuisance on ground transportation, and the confined nature of airplanes prevents passengers from escaping the noise of their neighbors.

Analysis: The statement in question acts as an intermediate conclusion. It is supported by the final two sentences, which describe the cramped conditions and lack of mobility on flights, and it in turn supports the main conclusion that the proposal is ill-advised. Notice how the author uses the ground-transportation comparison as a baseline to escalate the severity of the problem in the air. You can identify this role by seeing that the statement is both a claim requiring evidence and a reason for the final verdict.