抗利尿激素分泌异常的人体在一次性大量饮水后，可能会引起血浆渗透压下降和循环血量增多，导致水中毒．下列相关叙述正确的是（　　）

已知函数f（x）=πcos（$\frac{x}{4}+\frac{\mathrm{\pi }}{3}$），如果存在实数x₁、x₂，使得对任意实数x，都有f（x₁）≤f（x）≤f（x₂），则|x₁﹣x₂|的最小值是（　　）

    My name is Sam. I am a junior high school student. My school is close to my home, so I always go to school on foot. Classes start at 8 a.m., and I am seldom late. I like Geography best. I enjoy learning about different places in the world.

    In the morning, we usually study Chinese, Maths and English. We have our morning break at 9:50 a.m..  When the bell rings, I run to the playground with my best friends Tom and Jack. We often play games. Break ends at 10:10 a.m..

Lunch is from 11:50 a.m. to 12:30 p.m.. Afternoon classes end at 3:30 p.m. Then Tom, Jack and I take part in the school bank practice. We make great music together.

    I always have a good time at school.