听下面一段短文，根据短文内容选择最佳答案
16．How many sisters does the writer have？
A．One．
B．Two．
C．Three．
17．Where did the writer's family probably live？
A．In the countryside．
B．In a big city．
C．In a big building．
18．Why did the writer's mother have to do everything？
A．Because the father was busy outside．
B．Because her children were too lazy．
C．Because she had only one child．
19．When did the writer go to school？
A．At five．
B．At six．
C．At seven．
20．What can we learn from the passage？
A．The father came home late every day．
B．The kids liked doing housework very much．
C．The writer's family lived a hard but very happy life．