It would be "in contrast" since we are comparing the taste of oranges to lemons.
Answer:Dawson I believe.
Explanation: Because the entire sentence is telling you that they left Dawson making it the main focus of the sentence.
The adverbial phrase in the following sentence is "over the fireplace", since it describes the place where the portrait is. Adverbial phrases, among other things, give information about where things are.
I am not sure with the answer "Unless the adverb phrase or clause comes before the main clause which I highly doubt than you do not need any punctuation."
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