It's a matter of preparation — bolting down your water heater before an earthquake or actually reading the in-flight safety card before takeoff — but also of mental conditioning.
关键是准备——在地震前栓紧你的热水器或者起飞前认真阅读飞行安全手册——和精神训练。
2
The only thing new to your existing system is the hose coming down from the batch heater, the batch connect valve, and the “T” connector at the Hot Out valve to tie it all together.
整个热水系统中只有从批量加热热水器引水的软管、连接阀、以及接在止热阀（the Hot Out valve）上用作贯通的三通是新添加的。
3
The reflector (300) is shaped to reflect heat and light emitted down and to the sides of the heater back up to the glass top of the burner.