16. Paper money was in _____ use in China when Marco Polo visited the country in_____thirteenth century.
A. the; 不填 B. the; the C. 不填; the D. 不填; 不填;
17. –– Why did you look so __________ when you saw Tom?
––Oh, it’s almost ten years _________ we met last time.
A. excited; since B. exciting; after C. excitedly; since D. excited; since
