Fill in the blank in the sentence "Expectant mothers are more ________ to lung damage due to smoking." with the most appropriate word.

Introduction / Context:
This sentence completion question is about choosing a word that correctly describes the increased risk experienced by expectant mothers when exposed to smoking. The context is health, and the sentence states that these mothers are "more ________ to lung damage". You must pick a word that naturally fits with "to lung damage" and accurately conveys susceptibility.

Given Data / Assumptions:
The sentence is: "Expectant mothers are more ________ to lung damage due to smoking." The options are:

• vulnerable
• disposed
• sensitive
• affected

We assume the sentence aims to highlight higher risk or susceptibility in pregnant women.

Concept / Approach:
The key phrase to recognise is "more ________ to lung damage". In health and safety contexts, English commonly uses adjectives like "vulnerable to", "prone to", or "susceptible to" when talking about likely harm. Other options might fit grammatically but do not create a standard collocation or do not express the same nuance.

Step-by-Step Solution:
Step 1: Examine "vulnerable". It means exposed to the possibility of being harmed, physically or emotionally. The phrase "vulnerable to lung damage" is natural and clearly conveys that expectant mothers can be harmed more easily. Step 2: Check "disposed". The usual phrase is "disposed to" when referring to tendencies or attitudes, for example "disposed to help". It is not normally used for physical harm like lung damage. Step 3: Look at "sensitive". We often say "sensitive to smoke" or "sensitive to criticism", focusing on reactions. "Sensitive to lung damage" is not a standard phrase. Step 4: Consider "affected". We say "affected by lung damage", not "affected to lung damage". The preposition with "affected" would be wrong here. Step 5: Therefore, "vulnerable" is both semantically correct and collocationally strong.

Verification / Alternative check:
Substitute the options in the sentence:

• "Expectant mothers are more vulnerable to lung damage due to smoking." This sounds natural and precise.
• "More disposed to lung damage" is awkward and not idiomatic.
• "More sensitive to lung damage" is not the standard expression; we talk about sensitivity to smoke rather than to the damage itself.
• "More affected to lung damage" is grammatically incorrect; we would use "affected by".

This confirms that "vulnerable" is the best choice.

Why Other Options Are Wrong:

• disposed: Typically followed by "to" in contexts of mental tendency, not physical injury.
• sensitive: Works well with stimuli like "light" or "smoke" but not with "damage" as the object.
• affected: Requires the preposition "by" and describes a state after harm, not susceptibility before harm.

Common Pitfalls:
Students may be tempted by "sensitive" because it is commonly used in healthcare contexts, but subtle collocation differences matter. When reading English health articles, notice that "vulnerable to" or "at risk of" are standard for describing groups more likely to suffer harm. Memorising such patterns will greatly improve your performance in similar questions.

Final Answer:
The correct word is vulnerable, giving "Expectant mothers are more vulnerable to lung damage due to smoking."