Across the country
The adverb is "steadily", as it modifies the verb "rode".
Do you mean prepositional phrase??My brother came to Auckland on the train.In this sentence 'on the train' is a prepositional phrase
No, the word "train" is not an adverb.The word "train" is a verb and a noun.
The prepositional phrase is by train.
"Overnight" can be either an adjective or an adverb. Example as adjective: We took an overnight train. Example as adverb: That train operates overnight.
"By" can be an adverb, as in "We watched the train go by." "By" can also be a preposition, as in "We stayed in a cottage by the sea."
The adverb is the word "earlier."
You can drive across the US, you can take a bus across the US, you can fly across the US, you can take the train across the US.
I have been told by my freight forwarder that it means sending your container by train across country
At Amtrak.com you can book your train trip trip to any of it's destinations across the United States.
An adverb clause (adverbial clause) is a clause that describes a verb, adjective or adverb, in the same way that a single word, compound, or phrase acts as an adverb. They are subordinate clauses.Examples of adverb clauses:The boy laughed when the teacher's wig fell off.The bridge collapsed as the train rolled onto it.He is not awake until he has his first cup of coffee.