Explanation:
The first option, the others are normal
Essential amino acids are amino acids that must be supplied to one's body by their diet because they cannot be synthesized from scratch.
Answer: CO alarms have a life expectancy of around seven years. The CO alarm will beep every 30 seconds or display ERR or END. If a CO alarm is at its end-of-life, replacing the battery will not stop the beep. Most detectors will beep 4 or 5 times in a row about every 4 seconds. Do not mistake dangerous levels of poisonous gas for a detector with low battery.
Explanation: (credits to the internet) Hope this helped! :D
