WHO建议,按照60岁以上老年人口系数达到多少百位比为老年型社会()
A.5%
B.10%
C.15%
D.20%
E.25%
参考答案:B
下面两幅图反映的历史事件是( )
A.辛亥革命
B.国民革命
C.全民抗战
D.解放战争
While watching television, .
A.the doorbell rang
B.we heard the doorbell ring
C.there was someone knocking at the door
D.we heard the doorbell rung