You may be talking about a different kind of subject but I think this is what you were talking about:
A subject is the first part in a sentence about which the second part, the predicate, tells something. The subject performs an action, or indicates what or whom the sentence is about.
The answer is A cause the most effective type of research question
Answer: The theme is don't trust strangers with your money.
Explanation:
Crossing- present participle
Crossing the street is dangerous and illegal- phrase?
