—Can you lend me the book Passing by Your World?
—Sorry. I returned it to the library just now. Maybe it is still ________.
A:available
B:possible
C:saleable
Mary and Helen often f____although they love each other.
图是我国人口资料统计图表,据此判断下列叙述正确的是( )
年龄结构
年份
16岁以下
16﹣60岁
60岁以上
2000年
22.89%
66.78%
10.33%
2011年
16.60%
70.14%
13.26%
如图所示,若不计滑轮重量及摩擦,在几种提升重物的方法中最省力的方法是( )