Meaning: 'Painful' means causing physical or emotional pain, indicating that the night was filled with discomfort and distress.

Wrong options:

• cheerful: 'Cheerful' implies happiness and positivity, which contradicts the context of struggling with health, making it unsuitable here.
• restful: 'Restful' suggests a peaceful and relaxing night, which is the opposite of what is described in the context of struggling with health.
• meaningful: 'Meaningful' indicates significance or purpose, which does not align with the negative experience of a night spent struggling with health.

Correct answer: difficult

Explanation: The word 'difficult' appropriately describes the challenges he faced in continuing his duties, fitting grammatically and contextually with the sentence that follows about his struggle to maintain normalcy.

Meaning: 'Difficult' means hard to do or deal with, indicating that he found it challenging to continue with his duties due to his health condition.

Wrong options:

• enjoyable: 'Enjoyable' suggests a positive experience, which contradicts the context of struggling and makes it an inappropriate choice.
• simple: 'Simple' implies ease, which is contrary to the challenges he faced, making it unsuitable in this context.
• natural: 'Natural' suggests something that occurs without difficulty, which does not align with the struggle he is experiencing.

Correct answer: attend

Explanation: The word 'attend' fits grammatically and contextually as it refers to his inability to be present in class, which is directly related to his health condition and aligns with the overall context of the passage.

Meaning: 'Attend' means to be present at an event or gathering, indicating that he was not allowed to be present in class due to his health issues.

Wrong options:

• teach: 'Teach' implies the act of instructing, which is not the focus here; the sentence emphasizes his inability to be present rather than his ability to teach.
• leave: 'Leave' suggests departing from a place, which does not accurately reflect the context of being unable to attend class due to health.
• cancel: 'Cancel' implies calling off a class, which is not what is being described; he is unable to attend, not cancel.

Correct answer: happy

Explanation: The word 'happy' fits grammatically and contextually as it describes his emotional state regarding his desire to fulfill his responsibilities, contrasting with his inability to do so due to illness.

Meaning: 'Happy' means feeling or showing pleasure or contentment, indicating that he was eager and willing to attend class despite his health issues.

Wrong options:

• anxious: 'Anxious' implies worry or unease, which does not align with the sentiment of eagerness to fulfill responsibilities, making it unsuitable here.
• forced: 'Forced' suggests being compelled against one's will, which does not accurately reflect his desire to attend class; he wanted to attend, not feel forced.
• lazy: 'Lazy' implies a lack of effort or willingness, which contradicts his eagerness to fulfill his responsibilities.