The second tricky thing about the system set up, and the part that can be really annoying, is that only the fire alarm that first sensed the potential threat can turn the others off! Usually it's the one in the kitchen, reacting to blackened chicken smoke that didn't go up the vent ...
2) Everyone ___ (listen) carefully.Suddenly there ___ (be) a loud bang and the fire alarm ___ (go) off.3) I ___ (read) a book when the phone ___ (ring).4) While he ___ (swim) in the river,a snake ___ (bite) his leg. 扫码下载作业帮搜索答疑一搜即得 答案解析 查看更...