In 1999, the government spent about $ 39 billion to ______.
A. improve the prison conditions
B. keep men and women in prison
C. build houses for prisoners
D. maintain the prisons
正确答案：B
38．答案为B根据第一段最后一句thecostin1999forkeepingalltheseprisonersbehindbarsisabout$39billion作出该项选择theseprisoners指menandwomen
