I think it is answer choice D.
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
Answer:
CH3 + 2O2-----> CO2+2H2O
Na+ + Cl- ------> NaCl
4Al + 3O2------> 2Al2O3
N2+ +3H2 ------> 2NH3
(6,7,8) I can't see the small numbers
The answer should be C, they focus on using resources that can be renewed.
In order to become sustainable, industries have to maintain a balance between economic, social and environment. If they focus on only one or two aspects, they may not be able to become sustainable.
Economic aspects may include diversifying the ecomic structure; social aspects may include setting a minimum wage level for workers, providing a good working environment; and environment may include using renewable resources in production or handling their own pollutants.
Therefore, if they only focus on economic aspects such as maximizing productivity or profit, they may cause a lot of damage on the environment or even cause problems to the workers. So, the best answer is C. It also focuses on the environment, so that resources may be less likely to run out.
I think the answer would be survival of the fittest, the ones who can survive and reproduce successfully.
Hope it helps.
