Select the most appropriate word to fill in the blank.

______ they are twins, they are worlds apart in their attitude to life.

Although

The most appropriate word to fill in the blank is:

☀ Although

The sentence would read: "Although they are twins, they are worlds apart in their attitude to life."

Explanation: "Although" is used to introduce a contrast or contradiction between two clauses. In this context, it sets up the contrast between being twins and having different attitudes toward life. The other options don't fit the context:

• Despite: This is used to introduce a contrast, but it is typically followed by a noun or noun phrase, not a clause.

• Whereas: This is a conjunction that is used to show a contrast between two things, and it fits well in this sentence to introduce the difference in attitude.

• However: This is an adverb that can introduce a contrast or contradiction, but it doesn't fit the context as smoothly as "although" or "whereas."