9.The childs abnormal behavior puzzled the doctor.
A）bad
B） frightening
C）repeated
D）unusual
10.There is an abundant supply of cheap labor in this country.
A）a steady
B）a plentiful
C）an extra
D）a meager
11.In order to improve our standard of living，we have to accelerate production
A）step up
B）decrease
C）stop
D）control
12.Gas does accumulate in the mines around here.
A）increase
B）spread
C）collect
D）grow
13.Our plan is to allocate one member of staff to handle appointments.
A）assign
B）persuade
C）ask
D）order
14.Her behavior is extremely childish.
A）simple
B）immature
C）beautiful
D）foolish
15.We also want to use the water to irrigate barren desert land.
A）hairless
B）bare
C）empty
D）bald