The theme of the oval portrait is Fatal love, the wife in the story loves an artist but he loves his art. so by the time he was done it happened that she had died by his side.
The subordinate clause is "you must start researching now"
A common noun are words like house. Year
The question above is an excellent example of a word analogy. A word analogy is usually used to indicate the comparison of elements containing similarities in their definition. For the case above, it establishes the industry to its product thus the answer would be the third choice "cars."
