以下哪个国家是储蓄保障型社会保障模式的主要代表()
A.美国
B.英国
C.德国
D.新加坡
参考答案:D
若3a+2b=4,2a-b=5,则5a+b=______.
Among gastric juice, bile, pancreatic juice and small intestinal juice, which is the pest digestive juice and why?(4 Points)