问答题 图表种类 表格图 图表instruction The table below gives information about percentage of population over 60 in 6 regions and the whole world in 2000 and 2050. Summarize the information by selecting and reporting the main features, and make comparisons where relevant. 图表要素回忆 描述6大洲包括Africa, Europe, North America等在内的老龄人口的比例变化，有关2个年份，一个是过去时态，一个是将来时间预测。数据不多，难度也并不大。