21. --- What about ___ book? --- It’s too difficult ___ book for beginners.
A. the; the B. a; a C. a; the D. the; a
22. After many years both countries have come to realize that neither side could ever succeed in getting rid of _____ by means of war.
A. other B. another C. the other D. others
23. When we arrived in the middle of the night, there was no food ______ as all the shops were shut.
A. left B. available C. remaining D. convenient
