Beijing to Lanzhou Distance & Flight Duration: 2.5-hour Flight Explained

"How far is it from Beijing to Lanzhou?" It's a "2.5-hour flight" from Shanghai to Lanzhou. A. 2.5 hours' long B. 2.5 hours flight C. 2.5-hour flight D. 2.5-hour-long The correct answer is C. 2.5-hour flight. Option A, "2.5 hours' long," is not grammatically correct. The phrase should be "2.5 hours long" without the possessive apostrophe. Option B, "2.5 hours flight," is also not grammatically correct. The phrase should be "2.5-hour flight" with a hyphen. Option C, "2.5-hour flight," is the correct answer. It uses the hyphen to correctly modify the noun "flight" with the duration "2.5 hours." Option D, "2.5-hour-long," is not the best choice because it is redundant. The use of both "hour" and "long" to describe the duration is unnecessary.