Improve the bracketed part of the sentence: "It was so hot during the concert that some spectators passed (out)."

Introduction / Context:
This question tests your understanding of phrasal verbs in everyday English. The sentence describes spectators at a concert feeling unwell because of extreme heat. The verb passed is followed by the particle out, forming a phrasal verb that may or may not need improvement. Your task is to decide whether out is correct here or if another particle or phrase should replace it.

Given Data / Assumptions:

• The sentence is: It was so hot during the concert that some spectators passed (out).
• The options are away, by, over, and no improvement.
• The context suggests that spectators fainted or lost consciousness due to the heat.
• In English, to pass out is a well known phrasal verb meaning to faint.

Concept / Approach:
Phrasal verbs are combinations of a main verb and a particle that together create a specific meaning. The phrasal verb pass out means to faint or become unconscious, especially because of heat, exhaustion, or illness. This is exactly what the sentence wants to convey. Pass away means to die, which is much stronger and not intended in this mild context. Pass by means to go past something or someone, and pass over means to ignore or skip. None of these alternatives fits the meaning of fainting. Therefore, the phrase passed out is already correct and needs no improvement.

Step-by-Step Solution:
Step 1: Interpret the sentence: Extreme heat during the concert caused some spectators to faint.Step 2: Recall the phrasal verb pass out as the standard expression for fainting or losing consciousness.Step 3: Check pass away, which means to die, too strong and inappropriate here.Step 4: Check pass by, which means to go past in space or time and has nothing to do with losing consciousness.Step 5: Check pass over, which usually means to overlook someone or something, again unrelated to fainting. Therefore, the best choice is to keep out and choose No improvement.

Verification / Alternative check:
Imagine typical news or conversational sentences: Several fans passed out in the heat during the match. This is normal English usage and appears in newspapers and spoken reports. If we replaced out with away, we would be saying that several fans passed away, meaning they died, which is an entirely different and much more serious statement. Replacing it with by or over produces sentences with no clear or intended meaning in this context. The only combination that means fainting due to heat is passed out.

Why Other Options Are Wrong:
Option A away creates the phrase passed away, which is a euphemistic way to say died and does not match the lighter situation of discomfort at a concert. Option B by makes passed by, referring to movement and not to health. Option C over gives passed over, meaning ignored or not selected, as in passed over for promotion, which is completely wrong for describing the effect of heat on spectators. None of those phrasal verbs expresses fainting.

Common Pitfalls:
Sometimes exam candidates think that if a part of the sentence is in brackets, it must be wrong. However, many such questions include a No improvement option precisely to test whether you can recognise correct usage and avoid unnecessary changes. A good strategy is always to check whether the original phrase is already an idiomatic and commonly used expression. If it is, do not be afraid to choose No improvement.

Final Answer:
The phrasal verb passed out correctly expresses fainting due to heat, so there is no improvement needed and option D is correct.