The passage from Peking Dust that helps demonstrate the author's intention to shed light on the beauty of China is the last one:
But you must picture a Peking cart, of beautifully polished wood, natural color, and a heavy wooden body covered with a big blue hood.
This is the sentence that is trying to convey the beauty of this city through numerous descriptions of beautiful things.
I can hardly wait for the vacation to begin. - This is correct way to say that you are excited about the vacation.
The answer is B. It shows that Chang is happy about his test score.
Correct answer Children’s books