— What can ____ (he, she) do?
— She can fly.
读某地地形剖面图,回答下列问题。
A控制传染源 B切断传播途径 C保护易感人群
①接种甲肝疫苗____
②流感患者隔离____
③饭前便后洗手____
④为教室消毒____
⑤对饮水进行消毒____
My grandparents are ____ ____ the country life, and they wouldn't like to live with us.
用如图所示装置来测定空气中氧气的含量,对该实验认识错误的是( )