下列预防传染病的措施中，属于切断传播途径的措施是（   ）

选择合适的单词补全短文。

teacher;   man;  girl;  father;  woman

    Look! This is my family. The old ____ is my grandpa. And this is my ____. He is a teacher. The ____ in red is my mother. She is a ____, too. Who's that ____? Guess! Haha, it's me.

—Do you want to read this book?
—Well, I      it already．
   

文化在交流中传播。现代文化传播的主要手段是（   ）     

图A是氦元素在元素周期表中的部分信息，图B是氦原子的结构示意图，请回答问题．