Complete the following exclamatory sentence by choosing the most appropriate adjective: "What a _____ holiday!"

Introduction / Context:
This question tests your sense of correct collocations and natural usage in English. The sentence is an exclamation about a holiday and you must select the adjective that fits best in both meaning and tone. The correct answer will sound natural to a native speaker and convey the idea that the holiday was special or remarkable.

Given Data / Assumptions:
We are given the sentence:

• What a _____ holiday!

The options are:

• Momentous
• Memorable
• Momentary
• Immortal

Concept / Approach:
In English, some adjectives commonly collocate with holiday, meaning they are regularly used together in real speech and writing. When we want to praise a holiday, we often call it a memorable holiday, meaning it is worth remembering. The other adjectives have meanings that do not naturally fit a holiday. Understanding nuance and typical combinations is key in this type of vocabulary question.

Step-by-Step Solution:
Step 1: Consider the overall sentiment. The exclamatory structure "What a ... holiday!" usually expresses admiration or strong feeling about the quality of the holiday. Step 2: Examine Momentous. This word means very important or significant, often used for events like decisions, historical changes, or occasions of great impact. We rarely say "momentous holiday" in everyday speech. Step 3: Examine Memorable. This adjective means worth remembering, leaving a strong positive impression in the mind. A holiday that was enjoyable or special is often described as a memorable holiday. Step 4: Examine Momentary. This means lasting only for a very short time. A holiday is usually several days long, so calling it momentary does not make sense. Step 5: Examine Immortal. This means undying or living forever. It does not suit a temporary event like a holiday and therefore sounds unnatural. Step 6: Since Memorable fits both the meaning and the natural collocation, it is the best choice for the blank.

Verification / Alternative check:
If we read the sentence with each option, "What a memorable holiday!" sounds natural and expresses enthusiasm. "What a momentous holiday!" may sound forced and is rarely used. "What a momentary holiday!" is almost contradictory because holidays are expected to have some duration. "What an immortal holiday!" is stylistically awkward. Therefore, memorable clearly stands out as the option that would appear in standard English descriptions.

Why Other Options Are Wrong:
Momentous is wrong because it is used for highly significant events such as a momentous decision or a momentous occasion, not typically for a casual holiday. Momentary is wrong because it describes something that lasts for only an instant, which does not suit a holiday. Immortal is wrong because it refers to something that never dies or is eternal, which does not fit the idea of a holiday that has a beginning and an end.

Common Pitfalls:
A common mistake is to focus only on the positive tone and choose any impressive sounding word. However, vocabulary questions also check whether you know typical word combinations. Collocation is an important aspect of fluency. Learners should notice which adjectives regularly appear with holidays, events, journeys, and similar nouns when reading. This habit makes it easier to spot the natural choice in exams.

Final Answer:
The most appropriate adjective is Memorable.