(6)
A.usage
B.advantage
C.use
D.utilization

(9)
A.amount
B.quantity
C.bulk
D.number

(10)
A.set out
B.set up
C.set off
D.set back

(2)________
A.took on
B.took in
C.took off
D.took over

(11)
A.conscious
B.acquainted
C.familiar
D.accustomed

(13)
A.time
B.instance
C.date
D.occasion

(15)
A.method
B.order
C.trend
D.system

(17)
A.circumstances
B.occasions
C.incidents
D.situations

(19)
A.special
B.peculiar
C.specific
D.particular

(21)
A.direction
B.aim
C.search
D.view