A．信息归纳

    阅读短文内容。根据所提供的信息，完成信息卡内容。

    I am Lily，a student in Beijing．I am fifteen years old．My birthday is on July 6th．I like volleyball very much．I play volleyball with my friends after school．My mother is 42 years old．Her birthday is in June．She is an English teacher in a middle school．My father is 45 years old．His birthday is in October．He likes playing basketball．He can play it very well．

    Bill is my pen friend from the US．He is sixteen years old．His birthday is on March 8th．He likes Soccer and baseball．He likes ice-cream very much．He eats it every day．Bill always helps me with my English．I like him very much．

Information Card

已知等差数列$\left\{a_n\right\}$中，$a_7+a_9=16,a_4=1$，则$a_{12}$的值是  （   ）