Every ____(秋天)I go to visit my grandparents．They live in the countryside．It takes me____(四十)minutes to get there by train．They have a big____(农场)．I always spend much time staying with different kinds of animals and____(植物)in it．From day to night，I have many____(有趣的) things to do．Sometimes，I climb trees and draw some pictures of beautiful flowers．Sometimes，my____(爷爷)and I feed the animals such as our dog，cows，chickens and ducks，He____(帮助)me know a lot about them．It is also great fun to see the little ____(黄色的)chickens eating noodles and ducks swimming in the river．In the countryside，I can____(学习)a lot from playing．I am never____(劳累的)of the days there．

①给病人服用药物  

②给婴儿注射疫苗  

③对高烧的病人隔离观察  

④注意周围环境卫生，及时消灭蚊虫  

⑤经常开窗通风

已知三角形两边的长分别是2和3，第三边的长是方程x²﹣8x+12=0的根，则这个三角形的周长为____．

设抛物线$y^2=8x$上一点P到y轴的距离是4，则点P到该抛物线焦点的距离是（ ）