Answer:
The phrase in this sentence that is an adverbial phrase is: "For we are cut off from all the rest of the world."
Explanation:
Let's remember that an adverbal phrase is a group of two or more words that function as an adverb in a sentence. This adverbal phrase can describe a verb, an adeverb, or an adjetive. They usually answer questions such as How? Where? Why? or When?
In this particular example, the speaker says: "We are cut off from all the rest of the world", so this adverbial phrase answers to the question: How are we cut off? The response being: "We are cut off from all the rest of the world".
