Meaning: 'Little' means a small amount or degree, indicating that alcohol and opium were not very successful in alleviating pain during surgeries.

Wrong options:

• much: 'Much' implies a large quantity or degree, which contradicts the context of limited effectiveness in pain relief.
• great: 'Great' suggests a significant amount, which is inconsistent with the idea that these substances had minimal success in easing pain.
• title: 'Title' is unrelated to the context, as it refers to a name or heading, making it grammatically and contextually irrelevant.

Correct answer: remained

Explanation: The word 'remained' is the correct choice as it indicates that patients continued to be conscious during operations, fitting grammatically and contextually with the sentence structure. It suggests a state of being that persisted despite the use of laughing gas.

Meaning: 'Remained' means to continue to exist or stay in a particular state, indicating that patients did not lose consciousness during procedures.

Wrong options:

• contained: 'Contained' implies holding something within, which does not fit the context of patients' consciousness during surgery.
• retained: 'Retained' suggests keeping something, but it does not convey the same meaning as 'remained' in this context, which focuses on the state of being conscious.
• released: 'Released' implies letting go or freeing, which is not applicable to the context of patients' consciousness.

Correct answer: transported

Explanation: The word 'transported' is appropriate as it refers to the act of carrying or moving ether in heavy glass bottles, fitting both grammatically and contextually. It indicates the method of handling the substance, which is relevant to the discussion of ether's use in surgery.

Meaning: 'Transported' means to carry or move something from one place to another, in this case, referring to how ether was handled.

Wrong options:

• transmitted: 'Transmitted' refers to the act of sending or conveying, which does not fit the physical movement of ether in bottles.
• transparent: 'Transparent' describes something that allows light to pass through, which is irrelevant to the context of moving ether.
• translated: 'Translated' means to convert from one language to another, which is not applicable in this context.

Correct answer: because of

Explanation: The phrase 'because of' correctly introduces a reason, linking the potential lethality of chloroform to its effect on the heart. This fits grammatically and contextually, as it explains why some patients could die from its use.

Meaning: 'Because of' indicates the reason for something happening, in this case, the adverse effects of chloroform on patients' hearts.

Wrong options:

• due: 'Due' is typically used in a different grammatical structure (e.g., 'due to') and does not fit the sentence as it stands.
• rather than: 'Rather than' is used to indicate preference or contrast, which does not apply to the context of explaining a cause of death.
• but: 'But' introduces a contrast, which is not suitable here as the sentence is providing a reason rather than contrasting ideas.