在经济萧条时，财政可以通过( )来扩大需求，刺激经济发展。
A．减少福利补贴支出
B．增加政府采购
C．降低税率
D．提高财政补贴
参考答案：B,C,D
What a pity! Considering his ability and experience，he___ better．
A．need have done
B．must have done
C．can have done
D．might have done
聚乙烯包覆层防腐的优缺点？
