16. --Look at ____ animal. It’s interesting.
--Which one do you mean? ____ black one with a long tail?
A. an, The B. an, An C. the, The D. the, An
17. I'll go camping with you, if I ________ free tomorrow.
A. will be B. am C. shall be D. was
18. A friend of _____ came here yesterday.
A. my B. his C. him D. himself
19. --What does this sign mean?
--Let me see. It means _____.
A. FRAGILE B. GO UPSTAIRS
C. THIS SIDE UP D. EXIT