![](https://cos-cdn.shuashuati.com/pipixue-wap/2020-1230-1107-56/ti_inject-812ce.png)
To keep safe is very important. When you are alone at home, you should ______ to protect yourself. ①have a list of phone numbers to call for help, such as 110,119 and 120 ②play computer games while boiling some water ③keep the door locked ④pay attention to the gas, water and electricity ⑤let anybody in immediately when you hear the doorbell [ ]