A:燃放烟花爆竹时,远离人群和可燃物
B:正在使用的家用电器着火,立即用水浇灭
C:燃着的酒精灯不慎碰倒,立即用湿布盖灭
D:天然气泄漏,立即关闭阀门并开窗通风
4-____=____
Guangdong Province is in the ____ (south) part of our country.