21. The building was named Ford Hall in ______ memory of ______ European poet named James Ford.
A. 不填; a B. 不填; an
C. the; 不填 D. a; an
22. The boy was ______ at the ______ scene.
A. frightening; frightened
B. frightened; frightening
C. frightened; frightened
D. frightening; frightening
