设某动物由出生活到20岁的概率为0．8，活到25岁的概率为0．4．则现在年龄为20岁的动物活到25岁的概率为()．
A. 0．5
B. 0．6
C. 0．7
D. 0．8
E. 0．4
【B13】
A. in
B. of
C. for
D. about
【B12】
A. healthy
B. unhealthy
C. health
D. well
In ancient Rome, most people______.
A. lived in crowded tall buildings
B. lived in beautiful buildings
C. lived outside the city
D. led a life of wealth and comfort
微信支付 
支付宝支付