Ur totally right hunting is not a life of a koala
You can think about it this way:
If RT = WX, and we know that TW is the same measurement, that means that RT + WX = WX + TW.
The correct answer is A.
Nervous is the predicate adjective
This seems to be a declarative sentence. It talks about the reaction of the policeman to a specific thing. His expression is not pleasant. What he might saw is something not good and something to worry about. Other possible thing could be there an heinous crime scene that he faced at that moment. It depends on the situation.<span />
The answer is D. Hope this helps