21. A. any B. other C. the D. a
22. A. for example B. on average C. in fact D. by chance
23. A. with B. on C. in D. of
24. A. that B. those C. which D. what
25. A. because B. although C. in case D. so that
26. A. weak B. lost C. normal D. keen
27. A. mental B. physical C. biological D. psychological
28. A. territory B. land C. surroundings D. area
29. A. supply of B. call for C. cost of D. desire for
30. A. balanced B. restricted C. destroyed D. increased
