Name：Lu Yang

Age：41

Job：Doctor

Family：Mrs Lu is an actress (女演员). They have two daughters. They are happy.

Name：Tian Yu

Age：6

Job：Student  

Family：His father is an actor. His mother is a singer(歌手). His sister Tian Miao is nine years old. She is a student too.

Name：Mary Green

Age：54

Job：An English teacher

Family：Her husband Jack is a hotel manager. They have two sons and a daughter.

阅读下面材料，在空白处填入适当的内容(1个单词)或括号内单词的正确形式。

      “Equal pay for equal work” is a phrase by the American women who feel they are ____ (fair) treated by society.They think it is not right for women to be paid less than men for the____ amount of work.Some people say men have ____  (many) duties than women.A married man has to earn money to support his family and make important ____ (decide)，so it is right for them to be paid more.Some are even against married women ____ (work) at all.When wives go out to work，they say，the home and children are given no attention ____ ．If women are encouraged by equal pay to take up jobs，they will be ____ (able) to do the things that they are best at doing：making a nice home and bringing ____ children.Women who disagree say that they want to escape from the limited place which society wishes them to fill and have ____ freedom to choose between a job and home life，____ a mixture of the two.In fact women have the right not only to equal pay but also to equal chances.

某生物体细胞中含有12对染色体，在减数细胞分裂后形成的子细胞中，染色体的数目是（　　）