Answer:
This is a dependent clause.
Explanation:
A dependent clause is a group of words that contains a subject and verb but does not express a complete thought. A dependent clause cannot be a sentence.
"In his first year in the White House" does not express a complete thought, making it a dependent clause.
For one..
Idiom means; a group of words established by usage as having a meaning not deducible from those of the individual words.
For two; what are the answer choices?
For three; I will answer it when I get more detail.
-Promise.-
1) How to install an Electric Timer
2) The Growing Tuberculosis Epidemic in Africa